With the beginning of World War II, Poland was invaded by Nazi Germany and the Soviet Union, and initially the city came under Soviet occupation, as a result of the Molotov–Ribbentrop Pact. It was incorporated into the Byelorussian SSR from 1939 to 1941 as the capital of Belastok Region. Polish people were subject to deportations deep into the USSR (Siberia, Kazakhstan, Far North). In the course of the German invasion of the Soviet Union in 1941, Białystok was occupied by the German Army on 27 June 1941, during the Battle of Białystok–Minsk, and the city became the capital of Bezirk Białystok, a separate region in German occupied Poland, until 1944. The Great Synagogue was burnt down by Germans on June 27, 1941, with an estimated number of 2,000 Jews inside.