His comments came as Nato said reports from refugees who have fled Kosovo suggest that more than 3,000 Kosovo Albanians have been murdered by Serb security forces in the last three weeks.

During the daily Nato briefing, Brigadier General Giusseppe Marani showed aerial photographs of a site in Kosovo, near the village of Izbica, which he said was a mass grave.

General Marani said the site looked as if it could contain the bodies of up to 150 Kosovo Albanians.

Shame and disgrace

Mr Henderson told a Ministry of Defence briefing: "The guilty men in Kosovo will be brought to justice."

Kevin Connelly reports: "One more possible atrocity among many"

Detailed evidence had already been given by fleeing refugees of "systematic and repeated rape by Serbian police and soldiers", the massacre of around 60 elderly men and the forcible use of Kosovo Albanians as human shields to protect Serb anti-aircraft emplacements from air strikes, he said.

The Serb action had caused "outrage and revulsion throughout the civilised world".

Refugees have told of atrocities

Mr Henderson went on: "The young men who are committing war crimes on behalf of the Milosevic regime should think again.

"They should think about how long the Milosevic regime will last, about what will succeed the Milosevic regime.

"They should think about the shame and disgrace that they will feel in their 50s and 60s and what their grandchildren will think of a grandfather indicted for war crimes and spending his last years in prison.

Doug Henderson: "The guilty men in Kosovo will be brought to justice"

"These young men should think again today, their generals should think again, and so should President Milosevic."

Since it was established in 1993, the International Criminal Tribunal for the former Yugolsvia (ICTY) in The Hague had indicted 84 people for war crimes in Bosnia and Croatia, of whom 26 were in custody and seven had already been found guilty.

The Chief of the UK Defence staff, General Sir Charles Guthrie, said on Friday that mass graves were "continually" being discovered, with evidence from refugees and surveillance.

He said: "There are reports that thousands of young men have been murdered."

Tam Dalyell: War crimes threat counter-productive

There were stories from refugees of whole villages being massacred while other reports suggested that 50 men were shot dead in one incident, the general said.

However, Labour MP Tam Dalyell said talk of war crimes charges was counter-productive as it would only strengthen the determination of the Serbs.

Jeremy Bowen reports: "Aid agencies are at full stretch"

"It is unreal for Blair and other ministers to prattle on about arraigning President Milosevic and many other Serbs for war crimes," he said.

"If you knew that you were going to be had up as a war criminal, wouldn't it make you all the more determined to fight to the death, the more so because you knew that you could not be captured by ground troops?

"This is precisely what they will do."

Tony Lloyd: "All military action carries some risks"

Meanwhile, UK Foreign Office Minister Tony Lloyd has again ruled out sending in ground troops in an opposed invasion into Kosovo - despite hints of a shift in policy on Friday by Defence Secretary George Robertson, who is in the US for talks.

Bombing protest

He told the BBC Radio 4 Today programme: "The prime minister and all government ministers in Britain have been saying throughout the whole of this campaign that this is an air-based campaign."

Geeta Guru-Murthy reports: Protesters take to the streets

Hundreds of peace protestors marched through London on Saturday to demonstrate against Nato military action in the Balkans and Iraq.

The march had been arranged to protest against the sanctions against Iraq, but events overtook organisers.

Campaigners came from CND and other peace groups around the country.

They marched from Speakers Corner in Hyde Park along Park Lane to Trafalgar Square for a rally and speeches.

Marchers included Labour MPs Tony Benn and George Galloway and playwright Harold Pinter.