Clashes broke out when NATO peacekeepers began removing roadblocks erected by Serbs in July after Kosovo’s ethnic Albanian-dominated government tried to send border police to the mainly Serb north.

Western diplomats warn the impasse, with Serb resistance impeding the work of the EU’s police mission in Kosovo, could cost Serbia official candidate status for membership of the European Union when the bloc meets on Dec. 9.

“Two KFOR soldiers were wounded by firearms used by demonstrators,” said Frank Martin, a spokesman for NATO’s 6,250-strong Kosovo Force (KFOR).

“We have used a small amount of rubber bullets, tear gas and pepper spray”, he said. Television pictures also showed NATO using water cannon, and jostling with Serbs, some armed with sticks and wearing gas masks.

The German Bundeswehr said in a statement that two German soldiers had been wounded, “probably shot at with hand guns”. Security sources in Kosovo said one was shot in the hand and the other in the leg.

The clashes took place in the village of Jagnjenica, north of the ethnically divided town of Mitrovica. Medical officials in the north said at least 10 Serbs had been treated in hospital for wounds inflicted by rubber bullets.

Kosovo, where 90 percent of the 1.7 million people are ethnic Albanians, declared independence from Serbia in 2008.

But Serbs in a small slice of the north bordering Serbia reject the secession, and the West has struggled to tackle the country’s de facto ethnic partition.

The EU says the ex-Yugoslav republic must improve relations with its former southern province if it is to make progress towards accession, but Kosovo is steeped in history and myth for many Serbs who could punish the government in an election due early next year.

Officials from Serbia and Kosovo are due to meet in Brussels on Wednesday for a fresh round of talks, this time on two disputed border crossings in the north that are at the heart of the current dispute. Kosovo’s government tried to take control of them in July, but was repelled by armed Serbs.

Serbia’s state secretary for Kosovo, Oliver Ivanovic, was at the scene of Monday’s violence. Asked how the turmoil could affect Serbia’s chances of further EU integration next month, he replied: “This is very bad.”

Last week, 21 NATO soldiers were wounded, one seriously, in similar clashes.

Serbia lost control over Kosovo in 1999, when NATO bombed for 78 days to halt the killing and expulsion of ethnic Albanians in a two-year counter-insurgency war under then-President Slobodan Milosevic.

More than 80 countries, including the United States and 22 of the EU’s 27 members, have recognized the state, the last to emerge from the remains of old federal Yugoslavia.