The international community has appealed for calm in Kosovo after Serbs clashed with UN police in the worst outbreak of violence since Kosovo's independence that killed one police officer and injured dozens.
UN soldiers abandon a burning border control post in northern Kosovo
NATO peacekeepers and UN administrators on Tuesday warned Serbs hostile to Kosovo independence to end violent attacks on soldiers and police or face a "determined" response.
"Our soldiers came under direct fire ... we will not tolerate that any more," the NATO peacekeeping mission (KFOR) commander, General Xavier Bout de Marnhac, told a press conference in Pristina.
He said Monday's riots in the ethnically divided northern Kosovo town of Mitrovica had "crossed a red line with the deliberate intent to kill people -- you know Molotov cocktails, fragmentation grenades and direct fire" aimed at UN and NATO-led KFOR forces.
Town under de facto military law
The violence was sparked by a UN police operation to retake a UN court seized three days earlier by protesting Serbs. After the police detained around 50 of the Serbs, hundreds of residents from the Serb-dominated town attacked the security force's convoy and freed some of the prisoners.
A UN vehicle was set on fire during the unrest
The attacks prompted NATO to rush in with reinforcements ordering all UN police to withdraw and local Kosovo Serb police officers to suspend their duties. On Tuesday, NATO placed the Kosovo town of Mitrovica under de facto military law.
A 25-year-old Ukrainian UN policeman died of his injuries in a hospital on Monday evening. Another 63 international UN police officers were injured in clashes with angry Serbian protestors. Twelve seriously wounded French soldiers of the NATO-led KFOR force were flown back home for treatment.
KFOR spokesman Jean Luc Cotard said most of the injuries were inflicted by hand grenades in a "deliberate assault on our soldiers ... with the aim of killing."
Nearly 100 protesters were also injured, two of them critically, in riots in Mitrovica.
The UN administration has been struggling to impose control in the northernmost 20 percent of Kosovo's territory in which Serbs are the majority. Elsewhere in Kosovo, ethnic Albanians largely dominate.
The riots were not the first, but represented the worst outbreak of violence since Kosovo unilaterally declared independence from Belgrade a month ago. Kosovo is overwhelmingly Albanian but Serbs consider it a cradle of their civilization. The Balkan territory had been under UN administration since 1999 when NATO intervened to stop Belgrade's crackdown on separatists.
The deputy head of the UN administration in Kosovo, UNMIK, Larry Rossin, said the riots, as well as earlier "actions" by Serbs, were orchestrated, and warned the unnamed organizers that they would face murder and attempted murder charges.
"We know who they are, but can't say yet in the interest of the investigation," Rossin told reporters. "We will not tolerate this kind of violence ... it is totally unacceptable."
Leaders call for calm
Meeting with top Russian officials in Moscow, US Secretary of State Condoleezza Rice appealed to all parties involved to refrain from further violence.
Rice and Lavrov remained far apart on their positions on Kosovo
"I think we do agree that all sides should refrain from violence, and that all sides should refrain from any provocation. And we're sending a message to all sides appropriately," Rice said.
UN chief Ban Ki-moon deplored the violent attacks against UN and NATO-led forces and urged "all communities to exercise calm and restraint." He expected "all sides to refrain from any actions or statements that could incite or provoke further violence," a statement from his office said.
Russia, which remains Serbia's strongest ally in opposing Kosovo independence, stuck to its guns in the aftermath of the rioting.
Speaking at a joint Moscow press conference with Rice, Russian Foreign Minister Sergei Lavrov reiterated Russia's opposition to Kosovo's independence.
Kosovo Serbs' rights were being ignored and they felt like "strangers" in their own country, Lavrov said.
Russia insists a resolution of Kosovo's status can only come with the consent of both the Serbian and Kosovo governments.
Serbia blames NATO, UN for violence
Kosovo's independence is recognized by most world powers including the US and most of the EU including Britain, France, Germany and the former Yugoslav republic of Slovenia. Japan on Tuesday became the 28th country to recognize Kosovo as an independent state.
Serbia, which runs parallel structures of authority in northern Kosovo, with the town of Mitrovica the hub of economic and political life, on Tuesday blamed NATO and the UN for the violence, saying it was triggered by their retaking of the Mitrovica courthouse.
About 120,000 Serbs remain in Kosovo among two million ethnic Albanians. Almost half live in the north. Belgrade has instructed the Serb population there to boycott and ignore international and Kosovo authorities and has even condoned violent protests launched since Kosovo split from Serbia.
On Tuesday, most major Serbian newspapers portrayed the violence in Mitrovica as an attack on defenseless Serbs.
The violence has cast doubt on the deployment in the north of a European Union rule-of-law mission in the coming months which hopes to take over policing from the UN.