Mass grave uncovered that remained Nazi secret Between 1941 and 1945, the Nazis and their collaborators murdered some six million Jews across Europe. They killed roughly two-thirds of Europe’s Jewish population as the Nazis operated more than a thousand concentration camps in German-occupied Europe. The murders were carried out in a number of different ways, including extermination through labour in concentration camps , and in gas chambers and gas vans at extermination camps . Among the extermination camps were Auschwitz-Birkenau, which comprised more than 40 different concentration and extermination camps , Majdanek and Treblinka . All three were in German-occupied...