In September 1939, the "Einsatzgruppe I" entered the city to commit atrocities against Poles, and the "Einsatzgruppe zbV" entered to take over the Polish industry. Poles expelled in December 1939 from various places in German-annexed western Poland were deported in freight trains to Tarnów. On 14 June 1940, the first mass transport left the Tarnów station to Auschwitz concentration camp, with 728 Polish political prisoners, including at least 67 underage boys. All throughout the German occupation of Poland Tarnów was an important center of the Armia Krajowa (AK) and other resistance organizations. In the mid-1944, AK's 16th Infantry Regiment "Barbara" took part in Operation Tempest. After the Warsaw Uprising, in October 1944, the Germans deported 3,000 Varsovians from the Dulag 121 camp in Pruszków, where they were initially imprisoned, to Tarnów. Those Poles were mainly old people, ill people and women with children. The Wehrmacht retreated from Tarnów on 18 January 1945, and the city was captured by the Red Army, and then restored to Poland.