BELGRADE, March 17 (RIA Novosti) - Serbia has started consultations with Russia on joint action to end the ongoing violence in northern Kosovo, the Serbian prime minister said on Monday.

Over 100 people have been injured in clashes between Serbs and police in Mitrovica since United Nations police and NATO-led KFOR troops launched an operation this morning to regain control of the UN court building, seized last week by Serbs.

"Serbia has begun consultations with Russia on joint action to put an end to any violence against Serbs as soon as possible," Vojislav Kostunica said in a statement.

He condemned the use of force against Serbs in the province, who are protesting against "the pseudo-state within Serbia's territory."

The latest flare-up is the most serious between peacekeeping forces and Serbs since Kosovo unilaterally declared independence a month ago.

Serbian media quoted various sources as saying that around 70 people have been hospitalized in Mitrovica, including 15 in serious condition. Two men with severe injuries were sent to Belgrade.

Eight French troops from KFOR, 13 Ukrainian officers and 23 Polish police were also injured.

Early on Monday, the UN court building was surrounded and stormed by the UN police force and NATO peacekeepers.

The people occupying the building were former court employees who lost their jobs when Kosovo became a UN protectorate in 1999 after a NATO bombing campaign of Serbia to end a conflict between Serbs and ethnic Albanians. After forcing their way into the courthouse last Friday they hoisted two Serbian flags over the building.