LEPOSAVIC, Kosovo (Reuters) - NATO peacekeeping soldiers formed security cordons around four town halls in Kosovo on Monday to keep back Serbs protesting at ethnic Albanian mayors taking office in a Serb majority area after elections they boycotted.
In Zvecan, one of the towns, Kosovo state police - staffed entirely by ethnic Albanians after all Serbs quit the force last year - sprayed pepper gas to repel a crowd of Serbs who broke through a security barricade and tried to force their way into the municipality building, witnesses said.
In Leposavic, close to the border with Serbia, U.S. peacekeeping troops in anti-riot gear placed barbed wire around the municipality building to protect it from hundreds of angry Serbs gathering nearby.
"This morning, the NATO-led KFOR mission has increased its presence in four municipalities of northern Kosovo following the latest developments in the area," a KFOR statement said.
"In line with its mandate, KFOR is ready to take all necessary actions to ensure a safe environment in a neutral and impartial manner," it said, adding that KFOR's commander was in close contact with the security organs of Kosovo and Serbia.
KFOR troops also acted to protect the town halls in Zubin Potok and North Mitrovica from possible threats.
Serbs, who form a majority in Kosovo's north, have never accepted its 2008 declaration of independence from Serbia and still see Belgrade as their capital more than two decades after the Kosovo Albanian uprising against repressive Serbian rule.
Serbia has also refused to recognise an independent Kosovo.
WESTERN POWERS REBUKE KOSOVO OVER TENSIONS
Ethnic Albanians make up more than 90% of the population in Kosovo as a whole, but northern Serbs demand the implementation of a decade-old EU-brokered deal for the creation of an association of autonomous municipalities in their area.
Serbs refused to take part in local elections in April and ethnic Albanian candidates won the mayoralties in four Serb-majority municipalities with a 3.5% turnout.
Serbs have called on the Kosovo government to remove ethnic Albanian mayors from town halls and allow local administrations financed by Belgrade return to their duties.
On Friday, three out of four mayors were escorted into their offices by Kosovo police, who were pelted with rocks and responded with tear gas and water cannon to disperse the protesters.
The United States and its allies, who have strongly backed Kosovo's independence, rebuked Pristina on Friday for escalating tensions with Serbia, saying the use of force to install mayors in majority Serb areas undercut efforts to normalise relations.
On Sunday NATO Secretary General Jens Stoltenberg called on the Kosovo government to tone down tensions with Serbia. "Pristina must de-escalate & not take unilateral, destabilising steps," Stoltenberg said in a tweet.
After a phone call with EU foreign policy chief Josep Borrell, Kosovo Prime Minister Albin Kurti tweeted: "Emphasized that elected mayors will provide services to all citizens."
But Serbian Foreign Minister Ivica Dacic told RTS state television it was "not possible to have mayors who have not been elected by Serbs in Serb-majority municipalities".
NATO peacekeepers deployed in Kosovo after the alliance's 1999 bombing campaign that drove Serbian security forces out of Serbia's then-southern province, ending a brutal counter-insurgency campaign.
(Reporting by Fatos Bytici; writing by Ivana Sekularac; editing by Mark Heinrich)