3 September 1939 units from the Wehrmacht entered the town after the Battle of Grudziądz and then occupied it. From 26 October 1939 to 1945 the city was part of the administrative district of Regierungsbezirk Marienwerder in the new province of Reichsgau Danzig-West Prussia. Nazi atrocities Following the German invasion, the Einsatzkommando 16 and Einsatzgruppen IV and V entered the city to commit crimes against the population. They also carried out mass searches of Polish courthouses, organizations, police stations, etc., and seized large amounts of grain, textiles, coffee, equipment, and even homing pigeons. On 7 September, 25 Polish citizens were detained as hostages – priests, teachers and other members that enjoyed the respect of local society. They were threatened with execution if any harm came to the ethnic Germans from the city who were detained and held by the Polish authorities during the invasion of Poland. After their initial release on the return of the members of the German minority, they were re-arrested and most of them were shot. On 9 September a further 85 Poles were imprisoned by the Germans. The German authorities destroyed the city's monuments to Polish independence, and banned Polish priests from speaking Polish during church masses. On 4 September, the Einsatzgruppe V demanded a list of names of all members of the 600-strong Jewish community within 14 hours, as well as a list of all their possessions. They were also fined 20,000 zlotych On 6 September, the whole city was covered with posters demanding that Jews and "mixed races" of category I and IInd degree (so-called Mischlinge, i.e. persons of mixed race) gather at the headquarters of the Einsatzgruppe V (established in the local school). Around 100 people responded to the demand and were immediately arrested and robbed. After this they were transported to an unknown destination and disappeared – it is believed that they were most likely executed by the Germans in the Mniszek-Grupa forests. On 19 October, the city was visited by the NSDAP Gauleiter (regional chief) Albert Forster. In a public speech to the Volksdeutsche, he declared that the area was to become "one hundred percent" German, and that Poles "have nothing to do here, and should be evicted" Grudziądz was the location of the German concentration camp Graudenz, a subcamp of Stutthof concentration camp. Selbstschutz participation in mass murder Alongside the military and Einsatzgruppen administration, the first structures of Selbstschutz were