The Einsatzgruppen were mobile killing units formed by Nazi Germany during World War II. Their primary role was to carry out mass shootings of Jews, Roma, communists, and other groups deemed undesirable by the Nazi regime. These units operated mainly in Eastern Europe, following the German army as it invaded Soviet territories. Composed of SS and police personnel, the Einsatzgruppen conducted systematic exterminations, often forcing victims to dig their own graves. They were responsible for the deaths of approximately 1.5 million people between 1941 and 1943, contributing significantly to the Holocaust and the broader genocide perpetrated by the Nazis.