On April 10, Ustaše, aligned with Nazi Germany, declared the Independent State of Croatia (NDH) and claimed as part of its territory the entire area known as Bosnia and Herzegovina. In Drvar, this resulted in the beginning of the presence of the Ustaše government, the movement chiefly responsible for the World War II Holocaust in the Independent State of Croatia in which Serbs, Jews, Roma, Croat and Bosniak resistance members and political opponents were sent to concentration camps and killed. In the beginning the Ustaše contingent in Drvar consisted of the Croatian population residing in Drvar, but they were soon reinforced by others who came from outside Drvar.