For Operation Barbarossa, initially four "Einsatzgruppen" were created, each numbering 500–990 men to comprise a total force of 3,000. "Einsatzgruppen" A, B, and C were to be attached to Army Groups North, Centre, and South; "Einsatzgruppe" D was assigned to the 11th Army. The "Einsatzgruppe" for Special Purposes operated in eastern Poland starting in July 1941. The "Einsatzgruppen" were under the control of the RSHA, headed by Heydrich and later by his successor, SS-"Obergruppenführer" Ernst Kaltenbrunner. Heydrich gave them a mandate to secure the offices and papers of the Soviet state and Communist Party; to liquidate all the higher cadres of the Soviet state; and to instigate and encourage pogroms against Jewish populations. The men of the "Einsatzgruppen" were recruited from the SD, Gestapo, "Kriminalpolizei" (Kripo), Orpo, and Waffen-SS. Each "Einsatzgruppe" was under the operational control of the Higher SS Police Chiefs in its area of operations. In May 1941, General Wagner and SS-"Brigadeführer" Walter Schellenberg agreed that the "Einsatzgruppen" in front-line areas were to operate under army command, while the army provided the "Einsatzgruppen" with all necessary logistical support. Given their main task was defeating the enemy, the army left the pacification of the civilian population to the "Einsatzgruppen", who offered support as well as prevented subversion. This did not preclude their participation in acts of violence against civilians, as many members of the Wehrmacht assisted the "Einsatzgruppen" in rounding up and killing Jews of their own accord.