 With the beginning of World War II , Poland was invaded by Nazi Germany and the Soviet Union , and initially the city came under Soviet control , as a result of the Molotov @-@ Ribbentrop Pact . It was incorporated into the Byelorussian SSR from 1939 to 1941 as the capital of the <unk> Voblast . After the Nazi attack on 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 , Białystok was burnt down by Germans on June 27 , 1941 , with an estimated number of 2 @,@ 000 Jews inside . 
