The bitterly divided Kosovan city of Mitrovica has once again erupted in violence.

Three people were shot when up to 1,000 ethnic Albanians tried to enter the Serbian quarter.

They are being treated at a French army medical facility.

A spokesman for the K-For peacekeepers could not say if the injured were Serb or Albanian, or French Nato peacekeepers.

The protests often come to a violent end

The trouble began earlier on Thursday when ethnic Albanian refugees tried to resettle in the northern part of the city.

They said that Serbs there set fire to the tents the refugees were using while their houses were being repaired.

As darkness fell, hundreds of ethnic Albanian protesters gathered at the city's main bridge and tried to cross into the Serb quarters.

Most were stopped by a line of French K-For peacekeeping troops, but a small group managed to wade across the river and make it to the Serbian side.

Pistol or rifle shots were heard and eye-witnesses said that heavier arms were also used, perhaps including a rocket-propelled grenade.

French troops still guard the controversial crossing

It is not known who fired the shots, but K-For says that calm is now being restored by the French peacekeepers.

Nato officers have long believed that Belgrade has been steadily sending members of some of the most feared Serb paramilitary groups to Mitrovica - a development they fear could put the international peace mission there in serious jeopardy.

There have also been consistent rumours, widely believed on the Albanian side, that the Serbs have been stockpiling weapons in a warehouse, ready to be used in case of serious trouble.

Whatever the truth of this, Nato and the United Nations have made little progress in reconciling Serb and Albanian communities in Mitrovica and the situation there remains extremely tense.