In the spring of 1941, Heydrich and General Eduard Wagner successfully completed negotiations for co-operation between the "Einsatzgruppen" and the German Army to allow the implementation of "special tasks". Following the Heydrich-Wagner agreement on 28 April 1941, Field Marshal Walther von Brauchitsch ordered when Operation Barbarossa began that all German Army commanders were to identify and register all Jews in the occupied areas in the Soviet Union at once and to co-operate fully with the "Einsatzgruppen". Each "Einsatzgruppe", in its area of operations, was under the control of the Higher SS and Police Leaders. In a further agreement between the Army and the SS concluded in May 1941 by General Wagner and Walter Schellenberg, it was agreed that the "Einsatzgruppen" in front-line areas were to operate under Army command while the Army would provide the "Einsatzgruppen" with all necessary logistical support. Under the guise of "anti-bandit" ("Bandenbekämpfung") operations, the Wehrmacht in the Soviet Union massacred Jews and other civilians. Co-operation with the SS in reprisals and anti-Jewish operations was close and intensive.