German People's Union
The first phase of the action occurred in August 1939 when about 2,000 activists of Polish minority organisations in Germany were arrested and murdered. The second phase of the action began on September 1, 1939, and ended in October, resulting in at least 20,000 deaths in 760 mass executions by "Einsatzgruppen" special task units with help from regular "Wehrmacht" units. A special formation was created from the German minority living in Poland called "Selbstschutz", whose members had trained in Germany before the war in diversion and guerilla fighting (see: Deutscher Volksverband, the German People's Union in Poland). The formation was responsible for many massacres and due to its bad reputation was dissolved by Nazi authorities after the September Campaign with transfer to regular formations.