Thousands of Kosovo Albanians have gathered to mark the first anniversary of a massacre of 45 men, women and children at Racak.

Their bodies were found in the hills above the village last January. Many had been shot at close range - their faces were bloodied and disfigured.

The massacre strengthened Western resolve against Yugoslav President Slobodan Milosevic, despite official denials that Serbian forces had been behind the killings.

The mourners gathered at a snow-covered graveyard on the edge of Racak on Saturday, heaping flowers on the graves.

Hashim Thaci, the former leader of the Kosovo Liberation Army, said: "We have come to Racak, where all the world has seen what happened, where all the world first became convinced that Serbia had no intention of stopping its killings."

Veton Surroi, an independent Kosovo Albanian politician, said the killings had brought the 11-week Nato bombing campaign a step closer.

"[Racak] galvanised the pain we had been feeling at the time with an understanding of the international community that the only way to stop Milosevic was to show teeth."

Empty grave

One grave lay empty for Sahide Metushi, whose body has not been recovered.

Her son, Murat Metushi, said a witness had told him she had initially been wounded.

"But when a policeman saw that she was still alive, he simply executed her. They put her body in a plastic bag," he said.

"If we can find her body, it will be much easier for us. The blood of the people killed here, including my mother, brought freedom for Kosovo. But an empty grave is very painful."

The anniversary of the massacre comes as a team of Finnish forensic scientists nears the completion of a report on what happened. An inquiry published last March was inconclusive.

Ethnic clashes

Elsewhere in Kosovo, an explosion partially destroyed a Serbian Orthodox church in eastern Kosovo.

The blast in the predominantly ethnic Albanian village of Cernica also damaged houses owned by Serbs.

In a separate incident, international peace forces intervened between Serb and ethnic Albanian crowds in the north-western town of Mitrovica.

A K-For spokesman said two ethnic Albanians sustained head injuries.

The incidents reflecting the continued tensions between the ethnic groups more than six months after the arrival of Nato-led peacekeepers.

Mr Thaci urged Kosovo Albanians to build a tolerant democracy to serve as an example across the Balkans.

"We can't allow what Serbia did in Kosovo to happen here again."

A K-For spokesman has said a United States soldier serving with the international peacekeepers in Kosovo has been arrested in connection with the death of a young woman believed to be an ethnic Albanian.

The woman's body was found by an American army patrol on Thursday near the south-eastern town of Vitina.

A United Nations official, speaking on condition of anonymity, said the woman had been raped before being killed.

Correspondents say this is the first such incident since the Nato-led peacekeepers entered the province last June.