The segregation of Jews in ghettos culminated in the policy of extermination the Nazis called the Final Solution to the Jewish Question, discussed by senior government officials at the Wannsee Conference in Berlin in January 1942. As German forces captured territories in the East, all anti-Jewish measures were radicalized. Under the coordination of the SS, with directions from the highest leadership of the Nazi Party, killings were committed within Germany itself, throughout occupied Europe, and within territories controlled by Germany's allies. Paramilitary death squads called "Einsatzgruppen", in cooperation with the German Army and local collaborators, murdered around 1.3 million Jews in mass shootings and pogroms from the summer of 1941. By mid-1942, victims were being deported from ghettos across Europe in sealed freight trains to extermination camps where, if they survived the journey, they were gassed, worked or beaten to death, or killed by disease, medical experiments, or during death marches. The killing continued until the end of World War II in Europe in May 1945.