Some special camps of the Soviet State Security were established in the former concentration camps of the Nazi regime like Buchenwald and Sachsenhausen, but in the former prisoners-of-war camps or prisons as well. According to the report of the last Chief of the Department of Special Lagers in East Germany Colonel Vladimir Sokolov from March 1950 more than 157,000 people went through the special camps of the Soviet State Security in Germany. There were more than 122,000 German, up to 35,000 Soviet and 460 citizens of the other countries among them. (The citizens of the Baltic states were included in the figure of the Soviet citizens). More than 45,000 prisoners were released before 1950; up to 30,000 persons were deported to the GULAG camps in the Soviet Union and more than 43,000 prisoners died in the special camps during 1945-1950. More than 10,000 prisoners were taken to the Soviet Union without a sentence as a so-called special contingent.

They were mostly the Soviet citizens. 786 persons were sentenced to death and executed, 128 escaped, up to 7000 handed over to the task forces (оперативная группа) of the Soviet State Security or to the military tribunals and more than 14,000 were handed over to the Stasi of the GDR. Up to 6700 Germans were sent to the POW-camps. These figures are only the order of magnitude despite of the fact that the Soviet statistics had usually precise figures.

The first camps in Polish territory were set up by the Soviet NKVD soon after the front had passed. They were control-filtration camps, where primarily members of the Polish underground were held. After intense interrogations, most of them were deported to camps inside the Soviet Union, some were executed. The filtration camps existed for a short time, some were improvised in nature (prisoners were held in holes in the ground covered with barbed wire), the most well-known one was organized in the former German concentration camp Majdanek in Lublin soon after its liberation. Several times, prisoner rescues were attempted by the Polish underground, the biggest one happened on the night of 20/21 May 1945 in Rembertów.

Simultaneously, in Autumn 1944, the communist authorities started creating their own system of camps. They were supposedly prepared for Germans, the Volksdeutsche (Polish citizens, who declared German nationality during the war), and collaborators, later also prisoners of war. In reality, next to many random people, persons suspected of working with the underground were directed there. Also in this case, the infrastructure of German concentration camps was often utilized, among others that of subcamps of KL Auschwitz. At first, there was a high mortality rate in the camps, due to bad living conditions, contagious diseases, and torture. Later, the main cause of death were work accidents. 

In 1947, new categories of prisoners appeared in the camps. The Special Commission for Combating Misappropriation and Economic Sabotage sent alleged “speculator” (in reality mostly private entrepreneurs), people caught illegally slaughtering animals, "hooligans", and people spreading “whispered propaganda”. During the forced relocation of Ukrainians (operation “Wisła”), almost 4 thousand people were imprisoned in the Jaworzno camp. In the following years, the camps also received criminal and political prisoners, including members of underground organizations and farmers opposing collectivization. The total number of prisoners in the camps varied – in October 1945 it was about 31 thousand, in March 1947 – 80 thousand, in December 1949 – over 4 thousand, in November 1950 – 15 thousand, in December 1954 – 23.5 thousand. 

The camps system was often reorganized. Until 1954 it was administered by the Ministry of Public Security, later by the Ministry of Justice. At first, the system was based on Central Labour Camps, with subcamps subordinate to them. In 1948 they were transformed into Prisoners’ Work Centres of various categories. At first some of the prisoners worked on farms, but forced labour was primarily used in industry, the needs of which the camps network was adapted to. Prisoners worked mainly in mines (mostly coal), quarries, construction, and automotive industry.

The last forced labour camp was dissolved in 1958. Until then, there have been at least 206 camps of different sizes (not counting those subject to Soviet authorities). The total number of prisoners is estimated at 300 thousand, out of which 25 thousand died.

The history of the camp system in post-war Czechoslovakia can be divided into two stages. The first was related to the post-war settlements and the process of displacement of the German population. Part of this process was the creation of a network of camps, in the autumn of 1945, consisting of 372 sites (308 in the Czech Republic, 64 in Slovakia). In the following months, the number of camps and prisoners decreased rapidly. At first, entire families were imprisoned there, but soon the children were released. Some of the camps were used only for gathering the population prior to deportation, some for the internment of selected people, while others were used for forced labour. In total, there were about 200,000 people in the camps, over 90% of whom were Germans.

The second phase began after the Communists took full power via a coup in February 1948. In October, the act on forced labour camps (Tábory Nucené Práce, TNP) was adopted. Pre-existing facilities were partly used to create a new network of Communist labour camps. Special committees, and later also courts, sentenced people to imprisonment in the camp for a period of three months to two years just on the basis of an administrative decision, not a trial. The camps were initially subordinate to the Ministry of the Interior, later to the Security Service (Státní bezpečnost), and from June 1951 to the Ministry of Justice. The "anti-social elements" and "economic criminals" were to be targeted at the camps. In fact, camps became one of the main tools of political repression. In order to increase the number of prisoners, special repressive actions were organised, such as "T-43" (broadly understood "class enemies") and "D" (officers, non-commissioned officers and soldiers before 1948), but they did not bring the desired results. Political prisoners were also sent to the camps after they served their sentences in prisons.

In total, 30 camps were established in the Czech lands and 7 in Slovakia, and about 21,000 people passed through them. Regardless of the TNP, from 1949 there was also a system of camps under changing names (from 1954 Nápravně pracovní tábory – correctional labour camps). The last of them were closed in 1961-1962. Some of them replaced the liquidated TNP. The worst-known were the 17 camps in the vicinity of Jáchymov, Horní Slavkov and Příbram. The prisoners worked in uranium ore mines, which was then sent to the Soviet Union. Over 70,000 people worked in these camps, and it is estimated that half of them were political prisoners. Conditions were harsh, and additional punishments and torture were applied. 342 prisoners died, of which 31 were shot trying to escape.

In total, in the years 1948-1962, there were about 200 different types of camps, sub-camps and labour units of prisoners.
In 1950, after the liquidation of male religious orders, 15 places for the internment of members of religious orders were created. Some of the nuns who worked in designated places were also placed in this type of institution. Another form of forced labour (and at the same time a form of repression) was service in the Auxiliary Technical Battalions (Pomocné technické prapory, PTP), created in 1950. Until their liquidation in 1954, 60,000 men considered "politically insecure" were drafted to them. Instead of undergoing military training, they worked on construction sites or in mines.

In Yugoslavia, the Communist system started to be built already in the last phase of World War II. This means that the first camps were established already in 1944.  The first type of Yugoslavian camps were punishment or detention camps. There were about 40 of them all over Yugoslavia (including former Nazi camps, like Banjica). They were under the jurisdiction of the OZNA, the Yugoslavian secret police. In many cases these camps also served as camps for prisoners of war, too, but as prisoners of war were released, they became a place of punishment for those who had been declared enemies of the political system. 

The second type of camps were the so-called internment, collective and forced labour camps. At first, mainly civilians were sent here, people who had been members of other political parties, or were significant members of the intelligentsia or economic life. Later, as the war progressed, they became places for interning mainly the German and Hungarian minority groups. The first of them was established in Otočac, Croatia, in December 1943, by the partisans. The internment of Germans was ordained on 18 November 1944, then on 21 November they were deprived of their citizenship.

Between 1944 and 1948 approximately 170,000 Germans were interned in camps (mostly women and children). Some of the camps were just transitional camps, where Germans were collected before their relocation out of Yugoslavia. The internment of Germans in the Vojvodina province was finished by the middle of 1945. Although most of the camps were closed down in 1946, many camps for the internment of Germans were operating until 1948, some even until 1953. Those Germans who did not want to leave Yugoslavia were mostly released in 1948. The second biggest group of camp inmates were Hungarians, but there were representatives of other nationalities as well. The number of camps in Vojvodina is estimated at over 75. The death toll of camp prisoners in the whole Yugoslavia is estimated at 50,000 people. After Stalin-Tito split in 1948 more than 15 000 supporters of the Soviet version of communism were imprisoned in camps and prisons. Most of them were placed on the island of Goli Otok, famous for its harsh conditions. The prisoners were forced to do hard labour, were subjected to brutal ‘re-education' and were forced to report on each other. 287 of them died. The camp functioned until 1956, later a prison was built on its basis, which operated until 1988.

Many camps were overcrowded, and lacked beds and blankets. Forced labour camps were subordinate to the Directorate of Prisons, Camps and Colonies of the Securitate. Regardless of the possibility of imprisonment by an administrative decision, from 1950 persons requiring "re-education" ("enemies of the people") could be assigned to forced labour in "work units" for a period from 6 months to 2 years. "Work units" ("work battalions") were subordinate to the Ministry of the Interior, and any unauthorised desertion was punishable by imprisonment. They were dissolved in 1954, but in 1958 the possibility of sending selected categories of "enemies of the people" to forced labour (mainly in mines) was reintroduced. In total, this form of forced labour affected approximately 25,000 people. In Romania, as in the Soviet Union, the camp system was also accompanied by mass deportations and the forced settlement of entire groups of the population in selected places. Some of the camps were closed after Stalin's death in 1953. A year later, some prisoners were released. The amnesty of 1964 brought the end to forced labour camps.

On 20 December 1944, at the suggestion of the Communist Minister of the Interior Anton Yugov, and pursuant to Article 47 of the Constitution, the government issued an ordinance for the creation of special labour-educational detention facilities for “politically dangerous individuals”. In order to differentiate from the infamous Nazi camps, Bulgarian camps were euphemistically called Trudovo-vazpitatelni obshtezhitia (TVOs), a term translated in various publications as labour-educational communes, labour-reeducation communities, or reform-through-labour institutions (RLIs). Of course, in reality, the camps were not predominantly meant for criminals and “persons of loose morality.” By 25 July 1953, for instance, of the 1,917 prisoners being detained at the infamous Belene labour camp at that time, 1,730 had been sent there for “counter-revolutionary activities” and 187 for criminal activities. Everyone considered dangerous to the state security could be forcibly accommodated in the TVOs camps.

Mostly, labour camps were established near dams and railroads under construction, coal mines, quarries, as well as in some agricultural areas. For example, the first labour camp for opponents of the new regime was established as early as January 1945 in the town of Sveti Vrach (since 1947 Sandanski) in southwestern Bulgaria, where 800 detainees performed construction work on the Krupnik ‒ Kulata railroad.  On 30 May 1949, the Minister of the Interior issued an order for the establishment of the Belene labour camp situated on the Danube islands. The camp was closed down on 19 September 1953 and then re-opened in 1956. The reopening of Belene was clearly the reaction of the Bulgarian authorities to the 1956 explosion of discontent against the regime in Hungary. In 1959, the Belene camp was closed down again. Between 1964-1977 the Belene camp again became the site of forced labour for a small group of prisoners. In the years 1984-1987, representatives of the Turkish minority were imprisoned there.

Regarding the number of the forced labour camps in Bulgaria, even today it is not exactly clear how many there were. According to some authors, there were 86 camps in Bulgaria, others give smaller numbers. Data provided by an inquiry commission created in 1990 by the Bulgarian Communist Party showed that between 1944 and 1962 there had been about one hundred camps in Bulgaria. 

Also, evaluating the exact number of camp prisoners in Bulgaria during the Communist regime is difficult due to the insufficiency of archival documents. No one can say how many people met their demise there. Approximately 200,000 prisoners passed through the forced labour camp system. At the Belene camp, the prisoners’ corpses were fed to the pigs or washed away by the Danube, many of them having been left to rot before that in the toilets at the camp near Lovech. Most deaths were neither investigated nor documented. 

As the Communists took power in Albania in November 1944, the construction of a system of repressions began. Deportations and internment were widely used methods of fighting the “enemies of the people”. In 1945-1949, at least two massive internment camps existed in Berat and Krujë. Placed there were mostly families of political opponents, political prisoners, “kulaks”, members of the anti-communist resistance and collaborators from the occupation period. In 1949-1953 the central camp was in Tepelena, with around 2,300 deportees (women, old people and children), in a country the population of which didn’t exceed 1,200,000. The living conditions were extremely tough (hunger, diseases); it is estimated that about 300 children died in it during this period. At the same time there were a few smaller camps, e.g. in Porto Palermo (1949-1951). From 1954, internees were not enclosed in barbed-wire-fenced camps, but they could not leave the place of their internment. Due to this, the places were sometimes called “open camps”. Altogether, 59,000 people were interned until 1990; 7,000 of them died.

The internees were forced to work in the camps, but in 1946 a separate system of forced labour camps was being created. Next to camps which existed for a longer time (e.g. Maliq, 1947-1951), many were created temporarily, for a short time. From the very beginning, apart from prisoners of war, these camps were populated by political prisoners: so-called “occupational collaborators”, political opponents, anti-communist rebels, merchants who refused to hand over their gold, clerics, ex-bourgeoisie exponents, etc.

The prisoners worked in construction, factories, mines, and farms. In the 1950s the line between labour camps and prisons started to blur, since most of the latter were transformed into Units of Re-education through Labour. One of the most infamous ones was the “prison camp” Spaç (1968-1990). Its prisoners rebelled on 21 May 1973, and four leaders of the mutiny were executed. Forced labour remained one of the primary modes of punishment for both criminal and political prisoners until the fall of the regime. It is estimated that the number of political prisoners in Albania reached 34,000, out of which nearly a thousand died due to severe conditions.

After the Soviet Union occupied Estonia on 17 June 1940, the NKVD took over the penal institutions of the Republic of Estonia and reorganised them according to the Soviet model. When war broke out between Germany and the Soviet Union in June of 1941, most prisoners, including a number of criminal offenders who had been convicted in the Republic of Estonia, were evacuated to GULAGs in the Soviet Union. Hundreds of prisoners, whom the prison authorities were unable to evacuate or whom they did not even plan to evacuate, were shot.

The groundwork for restoring Estonian SSR NKVD penal institutions began in the Red Army rear area in the late spring and early summer of 1944. The first corrective labour colony began operating in Harku in a former prison complex. A transit camp with the status of a colony was formed in Tallinn in 1946. In total there were nine corrective labour colonies (ITK), camp departments (LO) and single camp stations (OLP) in the structure of the ESSR in 1945–1953. After the death of Stalin, general reorganisation of the system of corrective labour began. The transit prison, colonies and camp departments were placed under the jurisdiction of the Estonian SSR Ministry of Justice in April of 1953.

In addition to the above-mentioned, there were also several penal institutions in Estonia that were directly under the jurisdiction of central USSR authorities. Camp Department No. 1 was formed as part of the Gazslantsestroi construction trust for building the Kohtla-Järve oil shale factory. A corrective labour camp (ITL) was formed on 15 August 1946 for building Integrated Plant No. 7 (uranium factory) in Sillamäe in northeastern Estonia. The camp was under the jurisdiction of GULPS, the USSR MVD Main Administration of Industrial Construction Camps. The ITL and building in Sillamäe were reorganised in January of 1952 as ESSR MVD OITK single camp station. USSR MVD ITL and Camp District No. 6 of Building No. 256 were established in Aseri in northeastern Estonia in April of 1950. Its prisoners built a brick factory. It was disbanded in the spring and summer of 1953.

Political prisoners (so-called counterrevolutionaries) convicted according to Sect. 58 of the Russian SFSR Criminal Code were also held in Estonian prisons, but the vast majority were sent to other Soviet penal institutions, mostly GULAG camps. Political prisoners serving their sentences in Estonian penal institutions were brought there from other parts of the Soviet Union. There was no separate penal institution for political prisoners in the Estonian SSR, so they were distributed to all penal institutions. In 1945 and at the start of 1946, over half of the overall number of prisoners in two Estonian colonies had been convicted according to Sect. 58. By 1947, the relative proportion of political prisoners dropped below a quarter of the overall number of prisoners. The last prisoners in Estonia who had been convicted according to Sect. 58 were either released or sent to prison camps elsewhere in the Soviet Union in 1956.

In a secret annex to the Molotov-Ribbentrop Pact, Latvia was assigned to the Soviet sphere of influence. The Red Army occupied the country on 17 June 1940, and a few weeks later the newly created Latvian Socialist Soviet Republic was incorporated into the USSR.  Over the next year, around 3,000 people were arrested, some of whom were sentenced to GULAGs. On 14 June 1941, about 15,000 people with families were deported as “counter-revolutionary elements”. Most of them were forced to settle in remote regions of the Soviet Union. Over 5,000 people were imprisoned in the GULAG correctional labour camps.

Another wave of repression was brought about by the restoration of Soviet power in Latvia in the second half of 1944. In the years 1946-1950 alone, over 16,000 people were arrested for “counter-revolutionary crimes”; most of them became prisoners of the GULAG. From 1944, there was regional management of correctional labour institutions in Riga. At the beginning of 1945, only 217 prisoners were subordinate to it. Their number grew rapidly – in 1949 there were 8,895 prisoners. At the beginning of 1953, the number dropped to 4,314, in 1957 it was 1,776, and in 1960 there were 2,553. 

Most Latvians were not imprisoned within the Latvian SSR, but they were sent to camps in other parts of the Soviet Union. At the beginning of 1951, their total number was 28,520.

In the years 1944/1945 there were also NKVD filtration camps in Latvia, incl. in Jelgava, Riga, and Daugavpils. Mostly Latvians from units collaborating with the Germans were imprisoned there.

Since Lithuania was part of the Soviet Union, most prisoners who were interned had to serve their time in camps that were outside of Lithuanian territory (e. g. in the Siberian GULAG). That, of course, did not mean that punishment or corrective labour camps were not established here. Although Lithuania was annexed to the Soviet Union in 1940, because of the Nazi occupation between 1941 and 1944, the Soviet labour camp system was established between 1944–1951. Officially, the camps were aimed at criminal offenders, but they were mainly used to punish people for “counter-revolutionary crimes”. It is estimated that there were only about 300 criminal and recidivist criminals, while all others were convicted of so-called domestic crimes or non-payment of state taxes.

As a member state of the Soviet Union, the GULAG also extended to Lithuanian soil. Territorial units subordinate to the central authorities were organised at the republic level and included correctional colony and camp subdivisions whose prisoners were engaged in agricultural work, local industry, produced consumer goods and camp goods for internal use. In Lithuania, the Correctional Labour Colony Division had been operating since 1944.
In 1952, in Lithuania, the Department of Corrective Labour Colonies of the LSSR  consisted of three units, three labour camps.

Unit 1 was connected to the capital, Vilnius. It had three subunits. The first one operated on Rasų Street (Vilnius). It was established on 1 August 1944 and closed in 1953. According to archival sources in April 1952 there were 471 prisoners in this camp, though its capacity was only 200. The second subunit was located on Baltarusių Street (Vilnius) and was set up on 14 June 1951. In April 1952, 240 people were imprisoned despite its capacity being only 200. The third subunit was located in the suburbs of Vilnius, in Liubavas Village of Nemenčinė District (today Vilnius District). It was also established on 14 June 1951 and operated until 1953. Its capacity was also 200, but in April 1952 there were only 81 prisoners there.

Unit 2 was located in Pravieniškės Village of Kaunas District, established on 1 August 1944. In April 1952 there were 488 prisoners.

Unit 3 was operating in the district of Šilutė and it consisted of two subunits. One of them was the camp in Macikai Village. On 1 April 1952 there were 2,935 prisoners there, although the capacity was 2,314. Another unit was located on the Island of Rusnė and was established on 29 November 1951, closed in 1953. On 1 May 1952 there were 95 prisoners; the capacity was 200.

Besides the camps, there were three corrective labour colonies named 4th, 5th and 9th. 4th was located in Klemiškės Village, Klaipėda District, operated from 1946. The 5th was in the capital, Vilnius, and it operated until 1 April 1952. The 9th corrective colony was operating in the town of Naujojoje Akmenė from 1947. In total in 1952 there were 800 people imprisoned.

Besides the camps, there were three corrective labour colonies named 4th, 5th and 9th. 4th was located in Klemiškės Village, Klaipėda District, operated from 1946. The 5th was in the capital, Vilnius, and it operated until 1 April 1952. The 9th corrective colony was operating in the town of Naujojoje Akmenė from 1947. In total in 1952 there were 800 people imprisoned.

After World War I, the Bessarabia region, which since the 19th century had been within the borders of Russia, was incorporated into Romania. In 1924, a small Moldavian Autonomous Soviet Socialist Republic was established in the territory of Soviet Ukraine. Its existence was the basis for the Soviet claims to Bessarabia. 

These claims were fulfilled on the basis of a secret annex to the Molotov-Ribbentrop Pact. At the end of June 1940, the Soviet Union issued an ultimatum to Romania, which it accepted under pressure from Nazi Germany. The Moldavian Soviet Socialist Republic was established in the occupied territories (Bessarabia and northern Bukovina). It was recreated again in 1944, after the Soviet offensive.

The full number of people detained in the GULAG remains unknown. In early 1945, a regional board of correctional labour institutions was established in Chisinau. In 1949 it was in charge of 7,348 prisoners, in early 1953 3,049; in 1957 1,776; and in 1960 2,031. 

In 1951, a total of 22,725 Moldovans were imprisoned throughout the Soviet GULAG system.