On 29 and 30 September 1941, the Nazis and their collaborators murdered approximately 33,771 Jewish civilians at Babi Yar. The order to kill the Jews of Kyiv was given to "Sonderkommando" 4a, of "Einsatzgruppe" C, consisting of SD and SiPo men, the third company of the Special Duties Waffen-SS battalion, and a platoon of the No. 9 police battalion. These units were reinforced by police battalions Nos. 45 and 305, by units of the Ukrainian auxiliary police, and supported by local collaborators.