With the beginning of the Invasion of Poland on 1 September 1939, Selbstschutz units engaged in hostilities towards the Polish population and military, and performed sabotage operations helping the German attack on the Polish state. In mid-September, the chaotic and autonomous activities of this organization were coordinated by SS officers. Himmler placed Gustav Berger, a police official from Offenbach, in charge of the organization and district commanders in occupied zones made by the German army were put in place — West Prussia, Upper Silesia and Warthegau.