From the first days of the war , violence against civilians accompanied the arrival of German troops . In the September 1939 Częstochowa massacre , 150 Jewish Poles were among the circa 1140 Polish civilians shot by German Wehrmacht troops . In November 1939 , outside Ostrów Mazowiecka , around 500 Jewish men , women and children were shot in mass graves . In December 1939 around 100 Jews were shot by Wehrmacht soldiers and gendarmes at Kolo . Following the German attack on the USSR in June 1941 , Himmler assembled a force of some 11,000 men to pursue a program of physical annihilation of Jews . Also during Operation Barbarossa , the '' SS '' had recruited collaborationist auxiliary police from among Soviet nationals . The local '' Schutzmannschaft '' provided Germany with manpower and critical knowledge of local regions and languages . In what became known as the " Holocaust by bullets " , the German police battalions ( '' Orpo '' ) , '' SiPo '' , Waffen-SS , and special-task '' Einsatzgruppen '' , along with Ukrainian and Lithuanian auxiliaries , operated behind front lines , systematically shooting tens of thousands of men , women , and children , the Wehrmacht also participated in many aspects of the holocaust by bullets
Częstochowa massacre
Częstochowa massacre
The Holocaust in Poland