The NDH was divided by a German–Italian demarcation line, known as the "Vienna Line", with the Germans occupying the north and northeastern parts of the NDH, and the Italians the south and southwestern sections. The NDH immediately implemented genocidal policies against the Serb, Jewish and Romani population of the puppet state. Armed resistance to the occupation and the NDH itself initially formed into two loosely cooperating factions, the Partisans who were led by communists, and the Chetniks who were mostly led by Serb–chauvinist officers of the defeated Royal Yugoslav Army. In November and December 1941, almost all Partisan forces in the German-occupied territory of Serbia had been forced to withdraw into eastern Bosnia where they combined with local Partisan forces, mainly consisting of Serb peasants. Most of the Chetnik forces in eastern Bosnia were also local Serb peasants. The insurgency in eastern Bosnia meant that NDH authorities were unable to retain control of the region. At the end of 1941, there were six Partisan detachments in eastern Bosnia, with about 7,300 fighters operating in the Majevica, Ozren, Birač, Romanija, Zvijezda and Kalinovik areas. According to Enver Redžić, in early January 1942, the Chetniks controlled a large portion of eastern Bosnia, including the towns of Zvornik, Višegrad, Vlasenica, Srebrenica, Drinjača, Bratunac, Foča, Ustikolina, Goražde and Čajniče. Due to continuing cooperation between the two groups, the Chetniks also shared control of the towns of Rogatica, Olovo and Han Pijesak with the Partisans. The orders from "General der Artillerie" (Lieutenant General) Paul Bader, the German Military Commander in Serbia who also had responsibility for operational matters in the NDH, directed that Operation Southeast Croatia was to be an encirclement operation. All persons encountered within the area of operations were to be treated as the enemy. The population within the area to be targeted by the operation were almost all either Orthodox Serbs or Bosnian Muslims, although there was a small Catholic Croat minority. Bader believed that the Partisans and Chetniks were using the area as winter quarters, and that their presence there was a threat to major transport routes through eastern Bosnia.