Ethnic¹ Serbs have attacked and set fire to a security post on Kosovo's northern border with Serbia.

塞尔维亚人袭击并点燃了塞尔维亚与科索沃北部边境处一座保安岗位。

They reject Kosovan independence and were protesting over attempts by police to take control of the border.

After the Kosovo police withdrew, it appeared a deal had been struck and there was a lull²（间歇，暂停） , but the Serbs attacked again in the early evening.

Serbia's President, Boris Tadic, has urged an immediate³ end to the violence, calling the protesters "hooligans（小流氓） ".

The latest outburst prompted Nato peacekeepers to deploy⁴ at the Jarinje crossing, and at another crossing which they feared could also be targeted.

There are as yet no reports of injuries, but these are the worst clashes in several months, according to the BBC's Mark Lowen in Belgrade, Serbia.

One of the Kosovan police officers was killed and several others wounded in the initial operation, when local ethnic Serbs shot at them.

Appeal for calm

Previously⁵ the area was principally under the authority of the European Union.

It is Serb-dominated, however, and the police operation was motivated in part by dissatisfaction on the part of the Kosovan authorities in Pristina with the performance of ethnic Serb police officers who manned the border crossing.

Pristina also wanted to enforce a ban on Serbian goods from entering the territory, after an equivalent import ban from Serbia.

The police operation was criticised by the EU and United States as provocative⁶（刺激的，挑拨的） .

Nicholas Hawton, spokesman for the EU police mission in Kosovo, condemned⁷ the violence and appealed for people to remain calm.

But the Kosovan Prime Minister has defended the police actions as a legitimate⁸ attempt to assert control over the north, an area which has never accepted the mandate⁹（授权，命令） of the Kosovan government.

The same crossing was attacked in 2008, after Kosovo unilaterally（单方面地） declared independence from Serbia, a move still rejected by the Serb community.

Serbia refused to recognise the formal secession declared by the ethnic Albanian majority in 2008, and maintains close ties with the region north of Mitrovica, where ethnic Serbs have their main enclave（被包围的领土） .

On Thursday an urgent UN meeting will discuss the crisis.

The government in Serbia has warned that a tense night lies ahead in northern Kosovo - still one of the most unstable¹⁰ corners of Europe.