In June 1940, during the "AB-Aktion", the Germans carried out mass arrests of Poles, many of whom were afterwards imprisoned in the Lublin Castle and deported to concentration camps. From Radzyń, 6,000 local Jews were sent to Treblinka extermination camp in August 1942 amid gunfire and screams. Some went through the transit point in the Międzyrzec Podlaski Ghetto. The pacification actions were conducted by the Nazi German Reserve Police Battalion 101. The town was a major center of Home Army, with 4,200 members, and the German occupation lasted until July 23, 1944, when the Red Army entered the town. The Jewish community was never reconstituted.