On 6 April 1941 Germany, Italy, Hungary, and Bulgaria invaded Yugoslavia, and the Luftwaffe bombed Belgrade for 3 days killing 17,000 people. Belgrade was captured by German forces on 13 April 1941, and four days later on 17 April 1941 the Royal Yugoslavian Army surrendered unconditionally. Acting upon advice and with a heavy heart, King Peter II left the country to seek Allied support. He was greeted as the hero who dared oppose Hitler. The Royal Yugoslav Government, the only legal body of Yugoslavia, continued to work in London. The occupying Axis powers then divided Yugoslavia up. The western parts of the country together with Bosnia and Herzegovina were turned into a Nazi puppet state called the Independent State of Croatia (NDH) and ruled by the Ustashe. Most of the territory of modern Serbia was occupied by the German army and was governed by the German Military Administration in Serbia. The governed territory was called Serbia or the Territory of the Military Commander in Serbia, and, besides German military administrators, it was also governed by the Serbian puppet governments first under Milan Aćimović and then under Serbian army general Milan Nedić. The northern territories were annexed by Hungary, and eastern and southern territories by Bulgaria. Kosovo and Metohija were mostly annexed by Albania which was under the sponsorship of fascist Italy. Montenegro also lost territories to Albania and was then occupied by Italian troops. Slovenia was divided between Germany and Italy, which also seized the islands in the Adriatic.