The Russians shot back when fired on by Serbs they caught beating two wounded Albanians in the village of Korminjane.

It was the most violent incident involving peacekeeping troops since they arrived in Kosovo three months ago.

A spokesman for the Nato-led force, K-For, said the Russian soldiers went to the village of Korminjane after a gun fight broke out between Serbs and Albanians.

The soldiers returned fire after being shot at by the Serbs

The soldiers had found the Serbs beating two Kosovo Albanians who had been wounded in the battle.

When the Russians ordered the Serbs to stop, the Serbs refused and began firing at the soldiers. The soldiers then fired back at the Serbs, killing three people.

One Albanian also died during the earlier gun battle with Serbs.

Russians 'acted properly'

Nato Secretary-General Javier Solana told reporters in Pristina that the incident, which happened early on Monday in the American sector, proved that the Russian troops behaved according to the obligations of all K-For troops.

Javier Solana: Incident is proof of K-For teamwork

"Therefore they deserve the same respect that K-For troops from any other country deserve. We have one K-For, not two K-Fors. I think today is the proof of that."

The incident was the latest in what a K-For spokesman described as a worrying escalation of ethnically-motivated violence.

Two Albanians died over the weekend in separate attacks, and a Serb was killed by a bomb at his home in Pristina.

But the BBC's correspondent in the region says the shootings in Korminjane could serve to improve the reputation of the Russians among ethnic Albanians.

Russians under suspicion

The BBC's Nick Thorpe: "The latest in a series of ethnic killings"

There has long been a suspicion that the Russians would side with the Serbs, and troops are still being prevented from entering the town of Orahovac.

But Russian Colonel Mihail Kovtunenko commented: "This incident is a good example of how Russian peacekeepers came to Kosovo with a peacekeeping task in mind to normalise the situation in the region.