After the surrender of the Kingdom of Italy in September 1943, the German forces took over direct control of the region. In September 1944 the Soviet Union declared war on Bulgaria and occupied part of the country. A coup d'état on 9 September led to Bulgaria joining the Soviets. As result in the early October three Bulgarian armies, consisting of around 340,000-man, together with the Red Army entered occupied Yugoslavia and moved from Sofia to Niš, Skopje and Pristina to blocking the German forces withdrawing from Greece. The Bulgarians operated in conjunction with the Yugoslav and Albanian communist partisans. Kosovo was liberated by the end of November. It became a province of Serbia within the Democratic Federal Yugoslavia. The Kosovo Albanians, who had been promised self-determination if they joined the partisans, rebelled and martial law was declared. It took about six months for the area to be pacified after some 20,000 Albanians under Shaban Polluza resisted integration of Kosovo within Yugoslavia.