The demonstrators have suggested that they stay put until the results of a meeting between Slobodan Samardzic, Serbia's minister for Kosovo and Joachim Ruecker, head of the UN mission in Kosovo (Unmik).

The meeting is scheduled for Monday.

'Completely unacceptable'

Ruecker, however, has described the protest as "completely unacceptable".

"I have instructed Unmik police to restore law and order, and to ensure that the courts is again under UN control"

Joachim Ruecker, head of the UN mission in Kosovo
"I have instructed Unmik police to restore law and order, and to ensure that the courts is again under UN control," he said.

Serbs from the northern half of the divided city of Mitrovica broke into the municipal and district courts took down the UN flag on Friday.

Many of the Serbs had worked in Kosovo's judiciary before it came under Unmik administration in 1999.

UN police had that they had earlier been confronted by protestors pelting them with stones and metal objects.

Pieter Feith, envoy of the European Union and head of the EU mission in Kosovo, condemned the incident and said he was looking to the UN to restore order.

"I would like to appeal to them, to resist from further violence and to respect the mandate of the United Nations."

Action urged

Fatmir Sejdiu, Kosovo's president, and Hashim Thaci, the prime minister, demanded that Unmik and Nato peacekeepers should
react urgently.

They urged international authorities in Kosovo to "pull the hooligans out of the buildings as well as to provide permanent protection against them".

In February this year, Kosovo's government unilaterally declared independence from Serbia and has since been recognised by many western countries.

Serbia has declared the move as illegal and two days after the declaration angry Kosovo Serbs had torched two border crossings with Serbia.