These camps differed from Auschwitz and Majdanek, because the latter operated as forced-labour camps initially, before they became death camps fitted with crematoria.[11] Unlike "mixed" extermination camps, the extermination camps of Operation Reinhard kept no prisoners, except as a means of furthering the camps' sole purpose of industrial scale murder. The very few Jews who successfully escaped death (notably, only two at Bełżec),[12] were members of the Sonderkommando.