World War II halted the town's development because of Nazi and Soviet repression. The Germans captured Biała Podlaska on 13 September 1939, but withdrew on 26 September to allow the Soviets to a station in the town. But, on 10 October 1939, in accordance with the terms of the Molotov-Ribbentrop Pact, the Soviets departed and the town was reoccupied by the Germans. By that time, the Soviets had already completely plundered the PWS airplane factory, so that nothing but empty buildings remained. Poles expelled by the Germans in 1939–1940 from various places in German-annexed western Poland were deported to the area, while their previous homes were handed over to German colonists as part of the "Lebensraum" policy. In March and July 1940, the Germans imprisoned dozens of Poles in the local prison, and then massacred them in the nearby Grabarka forest. Over 40 Polish teachers were arrested in the town on 24 June 1940, imprisoned in Lublin and then deported to concentration camps, as part of the "AB-Aktion". On 5 July 1940 the Germans carried out another massacre of Poles in Grabarka, whom they previously imprisoned in the town. Further massacres of Poles were carried out by the Germans throughout the war. Despite such circumstances, the Polish resistance movement was active in the city. After Germany attacked their Soviet ally in Operation Barbarossa, a German prisoner camp was set up near Biała Podlaska, where many Soviet POWs were killed. In 1944 the town was recaptured by Polish and Soviet troops and restored to Poland, although with a Soviet-installed communist regime, which remained in power until the Fall of Communism in the 1980s.