Hundreds of Serbs have stormed a UN courthouse in northern Kosova, taking control of the site and hoisting a Serbian flag to replace the UN's.

The Kosovan Serbs broke through two entrance gates and pushed aside UN riot police, who did not intervene, in the Serb-dominated city of Mitrovica.

Most of the protesters left the yard of the building in the afternoon and there were reports that the UN flag had been hoisted again.

However, Serb judicial workers remained locked inside the courthouse saying they would not leave without a deal with UN authorities.

The most senior UN official in Kosova has said he has ordered the police to retake the courthouse, and pledged to defend his mandate as head of UN mission known as Unmik.

'Red lines'

"Those who turned to violence in North Mitrovica have crossed one of Unmik's red lines. This is completely unacceptable," Joachim Ruecker said.

"I have instructed Unmik police to restore law and order in the North and to ensure that the courthouse is again under UN control."

He said the attackers would be prosecuted and called upon Serbian authorities to prevent any further such incidents.

Many of the protestors had lost their jobs when the UN took over local institutions at the end of the war in Kosova in 1999.

The Serbs have held daily protests in front of the court since Kosova declared independence from Serbia on February 17.

The crowds have prevented international and ethnic Albanian judges from returning to work at the court.

Protesters' views

Miodrag Ralic, one of the Serb protest leaders, said: "We tried to negotiate, but no one wanted to talk to us. We could not wait any longer."

Nebojsa Jovic, another protest leader, said: "We have nothing against international judges. We want to co-operate with all non-Albanians and all those who do not recognize independent Kosova."

A spokesman for Kosova's police in Kosovska Mitrovica said the regional UN representative was negotiating with Serb leaders to deal with the situation.

Meanwhile, Jaap de Hoop Scheffer, Nato's secretary-general, arrived for his first visit to Kosova since it declared independence last month.

Scheffer met Hashim Thaci, Kosova's prime minister, and Fatmir Sejdiu, the country's president, at Nato's headquarters in the capital Pristina.

Sejdiu said he has urged Nato and the UN authorities to "react urgently and oust the hooligans from the building" and restore the UN flag.

The storming of the courthouse appeared to have been co-ordinated with the Serbian government in Belgrade, which has rejected Kosova's declared statehood and said it will assume authority in northern Kosova.

Belgrade has adopted an "Action Plan" on Kosova, which took effect after Kosova declared independence.

Concrete measures

Although concrete measures proposed in the plan remain secret, some of them were leaked by the local media, and included the takeover of the judiciary in the Serb-controlled regions of Kosova.

During earlier protests outside the court, UN and local staff were forced to evacuate after Serb rioters targeted the building with several small hand grenade explosions.

Since the declaration of independence, Kosova Serbs have already tried to take control of a stretch of rail line in northern Kosova in defiance of Kosova's government.

Hundreds of Serb policemen have handed over their badges and weapons rather than submit to Kosova authorities.

PHOTO CAPTION 

Riot police in Kosova.

Al-Jazeera