Mr Cook said the grave - largest found by British police working in Kosovo - was discovered inside a rubbish dump at Ljubidza, 6km north of the southern town of Prizren.

He did not indicate whether the bodies were believed to be ethnic Albanians or Serbs.

The discovery brings to 200 the total number of bodies found by British police and army personnel since the withdrawal of Serb forces from Kosovo.

The UK estimates that at least 10,000 people were killed in ethnic cleansing by Serbs during the recent conflict.

The latest disclosure came as the foreign secretary met the Kosovo Liberation Army commander Hashim Thaci in London to discuss the territory's future.

UK will pursue guilty

Speaking after the talks Mr Cook said the UK would turn over all the evidence, of alleged atrocities it had discovered, to the war crimes prosecutors.

"No country is more committed than Britain to bringing to justice those who carried out the atrocities that outraged the world and led to our action to make sure Belgrade could not continue that tragedy," Mr Cook said.

British troops and police are helping to gather evidence of alleged war crimes

"Already over the past two months that British team has exhumed 200 corpses from different sites, including many children, one of them as young as two."

Mr Thaci also condemned the killings, speaking through an interpreter, he said: "We feel terribly sad at the act of violence that took place. There were acts of violence against Albanians, against Serbs, against other groups."

He insisted the KLA was committed to demilitarising and becoming a civilian force by the 19 September deadline agreed with Nato.

The KLA would work with K-For to rebuild houses and schools in the war-torn territory, he added.

KLA reject revenge

Robin Cook and the KLA commander both condemned ethnic violence

Both he and Mr Cook stressed that they wanted to create a society in Kosovo which would include Serbs and ethnic Albanians.

"We want a multi-ethnic society, and we ask the Serbs to return to Kosovo to build a democratic society," Mr Thaci said.

"We're committed to establishing a society where tolerance will rule, not revenge," he said.

Mr Cook stressed that Britain wanted to work "with all ethnic communities in Kosovo to build a democratic and free, pluralist Kosovo which offers a future to all its people."

He added: "I have discussed violence against Serbs and other minority groups in Kosovo. We are both agreed that such violence and intimidation must stop.