About thirty German, Italian and Ustasha camps were founded in the territory of the Independent State of Croatia during 1941 and 1942. They were primarily intended as assembly, transit and emigration camps, though some operated as concentration camps.
From December 1941 the Germans ran Judenlager Semlin (the Jewish camp in Zemun) in the Independent State of Croatia and from 1943 ran the camps in Sisak, Vinkovci and Jankomir, just outside Zagreb.
Assembly camps for Jews were organised by the Italians in the areas under Italian control, in Kraljevica, on the island of Brač, in Hvar town and in Gruž, Kupari and on Lopud, near Dubrovnik.
In the area annexed to Italy, fascist camps for Croats, Serbs, Slovenes and Anti-Fascists (members of the Communist Party of Croatia and member of the People’s Liberation Movement) were built on the island of Molat near Zadar (founded in June 1942) and on the island of Rab (founded in July 1942).
The first Ustasha concentration camp in the Independent State of Croatia, Danica, was founded on 15 April 1941 near Koprivnica.
The Ustashas carried out the first mass liquidations of prisoners in Jadovno on Velebit and in the Slana and Metajna camps on the island of Pag, which formed the Velebit/coastal system of Ustasha concentration camps, with its headquarters in Gospić. They operated from the middle of June to 25 August 1941, when the Italians occupied this part of the Independent State of Croatia.
Along with Jasenovac Concentration Camp, which was in operation for the longest period, and in terms of prisoner numbers and surface area was the largest Ustasha camp, large camps were also founded in Krušćica, near Travnik, in Tenja, near Osijek, in Đakovo, Loborgrad, near Zlatar, and in Sisak.
The founding and operation of the camps fell within the competence of the Directorate for Public Order and Safety, established on 7 May 1941, or the Third Bureau of the Ustasha Surveillance Service, founded in August 1941.