Intelligenzaktion Pommern, a regional action in Pomeranian Voivodeship 23,000 Poles were killed. It was continued by the German AB-Aktion operation in Poland in the mid-1940s. The AB-Aktion saw the massacre of Lwów professors and the executions of about 1,700 Poles in the Palmiry forest. Several thousand civilian victims were executed or imprisoned. The Einsatzgruppen were also responsible for the indiscriminate murder of Jews and Poles during the 1941 German invasion of the Soviet Union. Communities were collectively punished for the purported Polish counter-attacks against the invading German troops. Mass executions of hostages were conducted almost every day during the Wehrmacht advance across Poland. The locations, dates and numbers include: Starogard (2 September), 190 Poles, 40 of them Jews; Swiekatowo (3 September), 26 Poles; Wieruszów (3 September), 20 Poles all Jews. On 4 September 1939 the 42nd Infantry Regiment (46th Infantry Division) committed the Częstochowa massacre with 1,140 citizens or more (150 of them Jews) murdered in wild shooting actions in several city locations. In Imielin (4–5 September), 28 Poles were murdered; in Kajetanowice (5 September), 72 civilians were massacred in revenge for two German horses killed by German friendly fire; Trzebinia (5 September), 97 Polish citizens; Piotrków (5 September), Jewish section of the city was set on fire; Będzin (8 September), two hundred civilians burned to death; about 300 were shot to death in Turek (9 September) Klecko (9–10 September), three hundred citizens executed; Mszadla (10 September), 153 Poles; Gmina Besko (11 September), 21 Poles; Kowalewice (11 September), 23 Poles; Pilica (12 September); 36 Poles, 32 of them Jewish; Olszewo (13 September), 13 people (half of the village) from Olszewo and 10 from nearby Pietkowo including women and children stabbed by bayonets, shot, blown up by grenades, and burned alive in a barn; Mielec (13 September), 55 Jews burned to death; Piątek (13 September), 50 Poles, seven of them Jews. On 14–15 September about 900 Polish Jews in parallel shooting actions in Przemyśl and in Medyka. Roughly at the same time, in Solec (14 September), 44 Poles killed; soon thereafter in Chojnice, 40 Polish citizens; Gmina Klecko, 23 Poles; Bądków, 22 Poles; Dynów, two hundred Polish Jews. Public executions continued well beyond September, including in municipalities such as Wieruszów County, Gmina Besko, Gmina Gidle, Gmina Klecko, Gmina Ryczywół, and Gmina Siennica, among others. In and around Bydgoszcz, about 10,000 Polish civilians were murdered in the first four months of the