The Soviet Union occupied Lvov in September 1939, according to secret provisions of the German-Soviet Pact. Germany invaded the Soviet Union on June 22, 1941. After a week of bitter fighting, German forces occupied Lvov. They discovered that the Soviet Secret Police had massacred thousands of prisoners, mostly Ukrainian nationalists, before fleeing from the city. This footage shows the removal of the bodies of some of those massacred. The Germans claimed that the city's Jewish population had supported the Soviets and had taken part in the executions. In the pogroms that followed the discovery, Ukrainian partisans supported by German authorities killed about 4,000 Jews in Lvov.