After the invasion , Hitler entrusted the SS with extermination actions codenamed Operation Tannenberg and AB-Aktion to remove potential leaders who could form a resistance to German occupation . The killings were committed by '' Einsatzgruppen '' ( task forces ; deployment groups ) , assisted by local paramilitary groups . Men for the '' Einsatzgruppen '' units were drawn from the SS , the SD , and the police . Some 65,000 Polish civilians , including activists , intelligentsia , scholars , teachers , actors , former officers , and others , were killed by the end of 1939 . When the army leadership registered complaints about the brutality being meted out by the '' Einsatzgruppen '' , Heydrich informed them that he was acting " in accordance with the special order of the Führer . " The first systematic mass shooting of Jews by the '' Einsatzgruppen '' took place on 6 September 1939 during the attack on Kraków
Operation Tannenberg
Operation Tannenberg
Schutzstaffel