The events were followed by German reprisals and mass executions of Polish civilians.[1][2] In an act of retaliation for Bloody Sunday, a number of Polish civilians were executed by German military units of the Einsatzgruppen, Waffen SS, and Wehrmacht.[3] According to German historian Christian Raitz von Frentz, 876 Poles were tried by German tribunal for involvement in the events of Bloody Sunday before the end of 1939.