MOSCOW, March 20: Russian President Vladimir Putin on Saturday denounced violence in the Serbian province of Kosovo as "ethnic cleansing" of the region's Serb minority and said Moscow had to adopt a tough position to halt it.

"Russia cannot merely watch what is happening there," Interfax news agency quoted Putin as telling a weekly ministerial meeting.

"Even our Western colleagues acknowledge that this is nothing other than ethnic cleansing. There must be a corresponding tough reaction in this instance to defend Serbs."

In Kosovo, additional Nato troops were on the ground as the Alliance struggled to prevent further violence in what it has termed "ethnic cleansing" by Albanians against Serbs.

The violence has forced around 900 Serbs in the UN-administered Serbian province to take refuge in NATO camps over the past few days, a source close to the multinational KFOR force said.

Admiral Gregory Johnson, NATO commander for southern Europe, denounced the violence, in which at least 28 people have died and more than 600 were wounded, as "ethnic cleansing".

Anger mounted in Serbia, the sovereign power in the province, which has been administered by the United Nations since the end of the 1998-1999 war between Serbs and ethnic Albanians.

At a service in Saint-Sava Cathedral in memory of the Serb victims, Amfilohije, the Metropolitan Bishop of Montenegro, placed all the blame on the Muslim, ethnic Albanian majority in Kosovo.

"To speak of inter-ethnic conflict in Kosovo is a big, hypocritical lie," he said. "What's happening in Kosovo is called a pogrom against a people and its history."

More than 200,000 Serbs fled Kosovo after the war, and only about 80,000 remain, guarded by about 10,000 UN and local police and the 38-nation, NATO-led peacekeeping force known as KFOR.

But they have come under heavy attack since Wednesday when a rumour that Serbs pushed three Albanian children into a swift-flowing river inflamed anger among the ethnic Albanians to the point of explosion.

Kosovo is a holy land for the Serbian Orthodox hierarchy.

A source close to KFOR said around 900 Serbs had taken refuge in NATO camps over the past few days after fleeing violence.

"Around 900 Serbs have taken refuge in KFOR camps and seven Serbian villages have been burned down," he said.

As violence spread, NATO nations rushed in reinforcements for the peacekeeper force, which has suffered more than 60 casualties.

Britain, France, Germany and other NATO countries pledged up to 2,000 extra soldiers, with orders to use deadly force if fired on.

A score of military transports landed in Kosovo on Friday night with troops and equipment to boost the 17,000-strong KFOR force.-Reuters/AFP