Violence fails to stop first ever Kosovo-wide election

It was also a test of EU attempts to normalise relations between Kosovo and Serbia.

Three ethnic Serb municipalities in north Kosovo - Leposavic, Zubin Potok and Zvecan - have for the past five years been ruled by Serb-funded de facto structures, paramilitary groups and criminal gangs.

But in April, Serbia agreed they should elect new local rulers who would fall under Pristina's central authority.

With Serbia keen to show the EU that it merits opening accession talks, the Serbian PM and President at the weekend urged Kosovo Serbs to follow the plan.

But despite the appeal, at around 5pm local time, masked men armed with baseball bats stormed into a polling station at a primary school in a Serb enclave in north Kosovo.

They hit people, reportedly breaking one woman's leg. They also smashed up ballot boxes and threw tear gas canisters. Two similar attacks took place at a technical school and at a medical school in the area at the same time.

The assault prompted the OSCE, a Vienna-based democracy watchdog, to end voting an hour earlier than scheduled and to evacuate its staff.

The attack was the climax of a campaign to sabotage the election by Kosovo Serb hardliners, which began in September with the murder of a Lithuanian policeman serving in the EU's rule of law mission, Eulex.

Ahead of the vote, on Saturday, Krstimir Pantic, a north Kosovo mayoral candidate, was beaten up outside his home.

Pro-boycott groups - with names such as the Chetnicks of Valjevo, DSS, Dveri and Obraz - also threatened people in the street and sent men to polling stations to film and photograph "traitors."

The baseball bat attack drew widespread condemnation.

"These destructive acts of hooliganism have no place in civilized and democratic societies and their perpetrators must be urgently held to account," Farid Zarif, a UN envoy to Kosovo, said on Sunday.

"Rule by thugs must never be accepted," Swedish foreign minister Carl Bildt tweeted on Monday morning.

But for his part, the OSCE mission chief, Claude Schlumberger, told press on Sunday the vote was a "success."

He noted that despite the boycott campaign, the Leposavic and Zubin Potok municipalities recorded a turnout of 22 percent, while Zvecan recorded 11.2 percent.

The boycott campaign was not entirely ineffective.

According to Kosovo's Central Election Commission (CEC), turnout among the 50,000 or so ethnic Serbs who live in the north was just 13 percent.

But the CEC noted that turnout in Kosovo's 33 other municipalities was around 60 percent.

By comparison, turnout in UK local elections in May this year was 31 percent. Turnout in the first round of French local elections in October was 33 percent.

"Overall evaluation of local elections in Kosovo: free, fair and progressive. More work to be done in north, but elsewhere Serbs voted well," Kosovo deputy foreign minister, Petrit Selimi, tweeted on Monday.