Along with other collaborationist military and paramilitary units, the SDS was used against the Partisans operating within the occupied territory. In late 1941, prior to the formation of the SDS, the Serbian gendarmerie had participated in the German-led Operation Uzice, which drove the Partisans and Chetniks from the Užice area. The SDS routinely executed captured Partisans, and frequently took and murdered hostages in towns and villages. The SDS also included former members of the gendarmerie that had assisted German troops to round up hostages to be shot at both Kraljevo and Kragujevac in October 1941. In July 1941, the Banjica concentration camp had been established in the suburbs of Belgrade. It was initially guarded by both the Gestapo and the SDS, but sole responsibility was eventually transferred to the SDS, who behaved sadistically and violently towards the inmates. Survivors of the camp stated that executions at the camp were carried out by both the Belgrade Special Police and the SDS, and that those executed included children. A total of 3,849 people were killed at the camp before it was closed on 3 October 1944. The SDS became increasingly unpopular with the population as time went on. Despite their limited independence, the SDS actively engaged in dehumanising Jews, Roma and communist Serbs, and in killing people from those groups or delivering them to the Germans for execution. They engaged in the execution of hostages both under Gestapo or Wehrmacht control and at their own initiative. The SDS clashed with other collaborationist formations at times, specifically Dimitrije Ljotić's Serbian Volunteer Corps ("Srpski dobrovoljački korpus" or SDK), and the Pećanac Chetniks loyal to "vojvoda" Kosta Pećanac.