Kosovo proper, the bombing campaign was soon extended to cover targets all over Yugoslavia, mainly military camps, but also including bridges, power stations, factories, broadcasting stations, and various military buildings. During the conflict, roughly one million ethnic Albanians were expelled or were forcefully driven from Kosovo, several thousand were killed (the numbers and the ethnic distribution of the casualties are uncertain and highly disputed). An estimated ten to twelve thousand ethnic Albanians and three thousand Serbs are believed to have been killed during the conflict. Some 3,000 people are still missing, of which 2,500 are Albanian, 400 Serbs, and 100 Roma. Some of the worst massacres against civilian Albanians occurred after that NATO started the bombing of Yugoslavia. Cuska massacre, Podujevo massacre, Velika Krusa massacre are some of the massacres committed by Serbian army, police, and paramilitary. The war also resulted in destruction of property, including many historical buildings. According to a report compiled by the U.S.-based Kosovo Cultural Heritage Project, Serbian forces destroyed approximately one-third of the mosques in Kosovo. According to the report, other historic structures associated with the culture and religion of Kosovo's Albanian population had also been singled out for attack by Serbian forces. The report also noted that damage from Nato bombs was limited and that, after the withdrawal of Serbian forces, many orthodox churches were destroyed by Albanians. According to a report by the Institute for the Protection of the Cultural Monuments of Serbia, some 160 cultural monuments in Serbia-proper were seriously endangered, damaged, or destroyed by NATO bombs, including twenty-five monasteries, thirty-four churches, three mosques, one synagogue, forty objects of city architecture, seven objects of folk masonry, twenty-five town centers, thirteen archaeological sites, and sixteen memorial monuments. Kosovo after the war After the war ended, the UN Security Council passed Resolution 1244 that placed Kosovo under transitional UN administration (UNMIK) and authorized KFOR, a NATO-led peacekeeping force. Almost immediately returning Kosovo Albanians attacked Kosovo Serbs, causing some 200,000–280,000 Serbs and other non-Albanians to flee (note: the current number of internally displaced persons is disputed, with estimates ranging from 65,000 to 250,000). Many displaced Serbs were afraid, at least initially, to return to their homes, even with UNMIK protection. By 2006 over 16,000 Serbs have returned to Kosovo. In 2001, UNMIK promulgated a Constitutional Framework for Kosovo which established the Provisional Institutions of Self-Government (PISG), including an elected Kosovo Assembly, Presidency and office of