Following the Soviet invasion of eastern Poland in World War II in fulfillment of the Molotov–Ribbentrop Pact, between 1939 and 1941 the Soviet NKVD conducted anti-Polish repression. It was preceded by a successful Soviet attack against a Polish partisan unit stationed in the Kobielne Wilderness. In 1940 the town had 3,985 residents: 3,670 Poles, 250 Jews, and 65 Belarusians. The NKVD arrested a number of Poles and their families and deported them to Siberia. The NKVD arrested and killed Parson Ryszard Marian Szumowski.