Polish and American peacekeepers exchanged fire with attackers in northern Kosovo late Wednesday and fired tear gas to disperse a mob of violent Serbs attacking an outpost at Kosovo's border post with Serbia, a NATO official said.
The violence erupted hours after Kosovo's special police ended an operation to take over control of two borders posts leaving once policeman dead. A mob of about 200 Serbs hurled firebombs and set a customs post ablaze soon after Kosovo police withdrew.
NATO responded by sending hundreds of troops in an attempt to quell the violence and came under fire as it did so, NATO spokesman, Cpt. Hans Wichter told The Associated Press. No injuries were reported.
"The gate is now clear," Wichter said, but added there was a risk of further attacks on the border post as around one hundred demonstrators are close to the checkpoint.
Additional French and American troops were sent to a second post bordering Serbia, also under threat of attack.
The violence is a setback for NATO-led efforts to broker a deal that would leave Kosovo officials in charge of the border crossings after special police units and local Serbs remove roadblocks.
NATO's Kosovo commander, Maj. Gen. Erhard Buehler is still talking to both sides in search of a solution, Wichter said.
Video shown on Serbia's state-run RTS television showed masked men demolishing the border post as European Union police leapt into cars and evacuated the area. The mobs attacked a crew from the official Serbian Tanjug news agency, seriously injuring one of two cameramen and slightly injuring another.
The attacks follow days of mounting tension between ethnic Albanians and minority Serbs after Kosovo Prime Minister, Hashim Thaci ordered special police units to take over two disputed border posts that were previously manned by Serb members of the police under EU supervision.
Thaci blamed the attack on Serbia's top leaders saying they want to partition Kosovo along ethnic lines.
"There will be no turning back and Serbia's plan for the division of Kosovo's north will never happen."
Earlier on Wednesday Kosovo authorities declared the operation over, and said special police units withdrew from the area.
Nicholas Hawton, spokesman for the EU police mission in Kosovo, condemned the attack and appealed for people to remain calm, while Serbia's President Boris Tadic also urged an "immediate end" to violence in the north of Kosovo, a statement from his office said.
"(The) hooligans who cause violence are not defending Serbia or the Serbian citizens," said Tadic. He also called on Kosovo Serbs to remain calm.
The European Union has condemned the police action that led to the rise in tensions in Kosovo.
Crowds of Serbs staged a similar attack on the same border posts in 2008 in reaction to Kosovo's declaration of independence.
The borderposts were torched and United Nations staff _ then in charge of the checkpoints _ forced to abandon them. Customs controls were never fully established ever since.
Nebi Qena reported from Pristina and Jovana Gec in Belgrade contributed to this report.