Insurgency in the Preševo Valley

The Insurgency in the Preševo Valley was an armed conflict between the Federal Republic of Yugoslavia and the ethnic-Albanian insurgents  of the Liberation Army of Preševo, Medveđa and Bujanovac (UÇPMB). There were instances during the conflict in which the Yugoslav government requested KFOR support in suppressing UÇPMB attacks since they could only use lightly-armed military forces as part of the Kumanovo Treaty that ended the Kosovo War, which created a buffer zone so that the bulk of Yugoslav armed forces could not enter.

The Yugoslav president, Vojislav Koštunica, often warned that fresh fighting would erupt if KFOR units did not act to prevent the attacks coming from the UÇPMB.

Background
The Kosovo War was a parallel conflict between the Yugoslav Army and the Kosovo Liberation Army. It began in February 1998 and ended on 10 June 1999 when the Kumanovo Treaty was signed. According to the treaty, KFOR troops, supervised by the United Nations, would enter as a peacekeeping force, while Yugoslav military forces were to withdraw. It was agreed that the KLA would disband by 19 September 1999. During the war, Serb forces had ravaged the area, and the Serb government disenfranchised the population; this united the local population against Serbs. The Preševo valley conflict erupted in June 1999.

Yugoslav
During the conflict, 18 members of the Yugoslav security forces were killed and 68 were wounded. 8 civilians were also killed. Some of the deaths were caused by mines.

UÇPMB
The number of UÇPMB casualties have been debated. Five insurgents were killed according to the UÇPMB. The Yugoslav government, however, reported that 30-40 insurgents were killed. About 45 Albanian insurgents surrendered to KFOR.

Other casualties
Two UN observers were wounded according to reports.