During the September , 1939 invasion of Poland Bischoff served as leader of '' Einsatzkommando 1/IV '' ( a sub-unit of Lothar Beutel 's '' Einsatzgruppe IV '' ) which was deployed in the northern Polish territories of Pomerania , Warsaw and Polesie . Bischoff 's unit was active in the towns of Jastrowie and Zambrów and was also involved in the bloody pacification of Bydgoszcz ( Bromberg ) along with the extermination of ethnic Poles carried out as part of Operation Tannenberg , the Nazi ethnic cleansing campaign targeting Poland 's intelligentsia and other members of the nation 's elite
Operation Tannenberg
Operation Tannenberg
Helmut Bischoff