The Babi Yar massacre occurred from 29 to 30 September 1941 when the German Einsatzgruppen and Ordnungspolizei, led by Friedrich Jeckeln, Otto Rasch, Paul Blobel, and Kurt Eberhard, worked with local Ukrainian collaborators to massacre 33,771 Jews at the Babi Yar ravine near Kiev, Ukrainian SSR during Operation Barbarossa. Kurt Eberhard, the military governor of Kiev, ordered for the city's Jewish population to be exterminated, and Sonderkommando 4a, the Sicherheitsdienst, SS police battalions, and the local Ukrainian police carried out the largest single massacre in the Holocaust to that date. 150,000 Jews, Soviet Red Army prisoners-of-war, communists, Ukrainian nationalists, and Roma would be executed in the same ravine on later dates, and all of the bodies were buried in mass graves.