During the German invasion of Poland, which started World War II, the "Einsatzgruppe III" entered the city on September 7–9, 1939 to commit various crimes against Poles, and also the "SS-Totenkopf-Standarte Brandenburg" operated in the city. During the German occupation of Poland, local Poles were subjected to mass arrests, imprisonment, deportations to concentration camps, expulsions, forced labour and massacres.