A Serb hardliner claimed victory as the first mayor of the northern part of the ethnically split city of Mitrovica on Sunday and laid out his agenda to keep Kosovo as part of Serbia, stirring fears that the vote will further estrange minority Serbs and majority ethnic Albanians.

Krstimir Pantic, head of the Serbian List, was a reluctant participant in the election organized by ethnic Albanian authorities because the Serb minority rejects Kosovo's 2008 secession from Serbia. But Serbia agreed to support the vote as part of an EU-mediated deal with Kosovo to normalize relations.

Many Serbs shunned Sunday's election. Pantic was quick to assure them that voting in the election was not an endorsement of Kosovo's independence.

"We have a common aim and that is to preserve Kosovo in Serbia," Pantic said minutes after the first preliminary results gave him a 10 percentage point lead over moderate Serb politician Oliver Ivanovic.

"We have changed the way we fight. We have not given up on Kosovo. We want to now fight through the institutions, whatever they are, they are the only ones through which we can achieve our legitimate and legal aims," Pantic said.

Pristina sees the vote as a way to bring the defiant Serb-run area under its control. The area has been an ethnic hot-spot since the end of the 1998-99 Kosovo war.

On Sunday, Kosovo police and international peacekeepers heightened security in the north of the country, after a vote last month was derailed when masked men opposing the vote attacked staff and destroyed voting materials. Authorities said no incidents were reported over the weekend.

In ethnic Albanian areas, the ruling Democratic Party of Kosovo lost support to the opposition Democratic League of Kosovo (LDK). But, the LDK lost the capital, Pristina, its long-time stronghold, to Harvard graduate Shpend Ahmeti from the ethnic Albanian nationalist Self-Determination movement.

The election took place in 25 out of 39 municipalities where no candidate managed to achieve a 50 per cent threshold for outright victory in the first vote on Nov. 17.

Kosovo fought a separatist war against Serbia in 1998-99 and declared independence in 2008 after almost a decade of being administered by the United Nations.

Serbia rejects the move.