In 2000 there was unrest in Kosovo, which was under United Nations Interim Administration after the adoption of the Resolution 1244 (10 June 1999), between the Kosovo Force (KFOR), Kosovo Albanians and Kosovo Serbs.
Resolution 1244 was determined to resolve the serious humanitarian situation and ensure that all refugees could safely return. It condemned violence against the civilian population as well as acts of terrorism, and recalled the jurisdiction and mandate of the International Criminal Tribunal for the former Yugoslavia (ICTY). It also recalled the sovereignty and territorial integrity of the Federal Republic of Yugoslavia (FRY), at the same time calling for autonomy for Kosovo. The resolution authorised an international civil and security presence in Kosovo. The Resolution affirmed the need for immediate deployment of international civil and security presences, and authorised the establishment of the Kosovo Force. The responsibilities of the international security presence included deterring new hostilities, monitoring the withdrawal of the Yugoslav Army, demilitarising the Kosovo Liberation Army (KLA), and ensuring a safe environment in which refugees could return.
Kosovska Mitrovica became de facto partitioned, the institutions of the Serb-inhabited north part of the town and North Kosovo being funded by Serbia. UN Special Representative Bernard Kouchner said of the division: "you have to think of the Serb reaction. The only place they feel protected is in the north—that's simply the fact". Violent riots in October 1999 by Albanians led to 184 injured and 1 death after Serb resistance to an attempt in September to escort Albanians over the Ibar bridge. The UNMIK accepted the KLA's transformation into a civil security force numbering 5,000 personnel, the Kosovo Protection Corps (KPC), in September 1999.
The Ibar river bridge which divided the town became the site of violent clashes between the KFOR, Albanians and Serbs. A Yugoslav police officer and physician were killed, and three officers and a physician were wounded in February in Kosovska Mitrovica. A UN bus transporting Serb refugees in Mitrovica was hit by an anti-tank missile, and a grenade was thrown into a Serb café the same month. The Serbs rioted, and eight people were killed (7 Albanians were killed in one incident, as reported on 5 February), UNMIK vehicles burned, and French KFOR soldiers injured. Between 2 and 20 February some 1,700 Albanians, Turks and Bosniaks fled North Mitrovica. On 16 February, Albanians attacked a bus convoy killing 10 Serbs. Following the February unrest, the KFOR increased its numbers, which up until then was 30,000. Violence continued, however, and UNMIK and KFOR were criticised for failing to protect Serbs.
Meanwhile, the KFOR saw the Liberation Army of Preševo, Medveđa and Bujanovac (UCPMB), an Albanian separatist organization in south Serbia, training in the Ground Safety Zone (GSZ). Some KLA veterans were part of the UCPMB. The UCPMB attacked local police, intending to cede Albanian-inhabited areas to Kosovo.
On 8 March, the FRY complained about the escalation of violence in the region, evidence that according to them, supported that the KLA was still active. On 15 March another FRY complaint protested KFOR establishment of an extended security zone in North Mitrovica, during which 16 Serb civilians were injured by stun grenades and tear gas. The FRY saw KFOR's actions as supporting the Albanians, pressuring Serbs to move out of Kosovo, and expected that they ensure minimum security and normal living in Mitrovica, "the last Serb refuge in Kosovo and Metohija". The French KFOR was met with controversy, their risk-averting measures being called "cowardice", straining relations with other KFOR troops and the UNMIK; Danish soldiers complained and UN police felt abandoned. An example of French inaction was an event in June 2000, when a Serbian mob trapped a small group of Albanians and American police officers, then attacked an American colleague trying to reach them, 10 m from a French checkpoint – the French troops withdrawing to their vehicles. Between April and September the FRY issued several documents to the UN Security Council about violence against Serbs and other non-Albanians. On 6 June, a grenade was thrown at a crowd of ethnic Serbs waiting for a bus in the town square of Gračanica, injuring three people, which was followed by some civil unrest.
On 22 January 2001, a group of armed Albanians attacked a police station in Macedonia, killing a police officer and injuring three others, thereby starting the insurgency in the Republic of Macedonia. The insurgent NLA was organized from former KLA fighters from Kosovo and Macedonia, UCPMB fighters, young Albanian radicals and nationalists from Macedonia, and foreign mercenaries.
In February 2001, enraged Albanian mobs routed French troops and torched KFOR armoured vehicles after an Albanian child had been killed in northern Mitrovica, believing it was a provocation by the Serbs. The victim was a 15-year-old boy who was killed in a grenade attack, which amidst Serb refusal to allow the return of Albanians in North Mitrovica sparked several days of riots.
On 8 April 2002, local Serbs attacked and injured 26 UNMIK police setting up a checkpoint in North Mitrovica. The UNMIK established its administration in northern Mitrovica on 25 November 2002.
Although crime rates decreased in 2003, violence and crimes against minorities were concerning. On 12 April 2003 a bomb exploded on a railway bridge in Northern Kosovo, killing two, including the planter, a KPC officer; an Albanian extremist organization took responsibility. On 17 April the Special Representative defined the group as terrorist. On 19 May a Kosovo Serb politician from Klokot was murdered and two elderly Serbs assaulted. On 4 June three Kosovo Serbs were murdered in Obilić. In August 2003, explosive devices planted in the Serb enclave of Klokot destroyed five Serb houses, with several injuries, including two American KFOR soldiers. On 13 August two Serb youths were killed and four wounded in a shooting in Goraždevac. On 18 August a Serb male died from wounds sustained from a shooting on 11 August, and another was seriously wounded in a shooting in a returnee site near Klina. On 31 August, four Serbs were injured and one killed in an explosion attack in Cernica near Gnjilane. The violent incidents further heightened the feeling of insecurity in the Serb minority, while UNMIK police took security measures in minority areas. Crime against UNMIK increased, with a police officer killed in the north by sniper on 3 August, while a KPS officer was murdered near Djakovica on 6 September, and another KPS officer was shot at in Pristina on 10 September. The violence level increased steadily since late 2003. On 17 March 2004, a violent unrest broke out in Kosovo.