James Robbins: "Britain is trying to force the pace"

Belgrade has denied responsibility for two cases of atrocities, and says its military operation against ethnic Albanian separatists is over.

In particular, the outspoken Deputy Prime Minister, Vojislav Seselj, accused the BBC of being part of a conspiracy to harden public opinion in the West, and warned of reprisals around the world if Nato forces attacked Serbia.

A Serb television report described the BBC accounts of atrocities committed by police in Kosovo as lies and manipulation.

Third massacre reported

David Loyn: BBC accused of laying ground for western air raids

The comments from Belgrade came after the emergence of evidence of a third Kosovo massacre this week.

Four men were slaughtered when Serb security forces ambushed a convoy of Albanian refugees in south-western Kosovo, according to Human Rights Watch.

Yugoslavia insists its offensive in Kosovo is over

A monitor from the group said one man appeared to have been shot at close range and another had had his nose cut off.

It follows earlier reports of the killings of 32 Albanians at two sites in the Serbian province.

Human Rights Watch said police detained several hundred men during the attack on Tuesday and burnt large parts of the village of Vranic.

Britain calls Security Council into session

The emergency meeting of the Security Council on Thursday was requested by Britain after reports of this week's massacres.

Graves were marked only by shoes

The bodies of 18 ethnic Albanians were found in the central Kosovo village of Gornje Obrinje and another 14 corpses were located in Vucitern.

Local people said the killings had been carried out by Serbian police.

The victims were stabbed or shot and several had been decapitated.

One child survived, protected from the bullets by the body of its mother.

Foreign Secretary Robin Cook says Britain is now seeking agreement for military action against Yugoslav authorities.

British Foreign Secretary Robin Cook: "This was an act of ethnic hatred"

"Britain is ready to act if Milosevic does not act in order to bring himself into line with United Nations resolutions (for a cease-fire).

"I think what we have seen is plain murder. Milosevic has outraged the whole of the world community," he told the BBC.

Mr Cook has demanded that the Serbs allow independent forensic investigation of the massacres.

Timetable for action

Rob Watson: "The meeting is likely to produce some very voluble and angry criticism, but not much else"

The BBC's UN correspondent, Rob Watson, says the Security Council meeting is certain to produce angry criticism of Belgrade.

But substantial action is unlikely before the Secretary-General, Kofi Annan, presents a report next week on Serbia's compliance with UN demands for a cease-fire in Kosovo.

BBC Diplomatic Correspondent James Robbins says Russia - who has traditionally stood by the Serbs - is likely to give its active support to this new denunciation of Belgrade.

That will strengthen Nato's hand as ships and planes prepare for possible cruise missile and bomb attacks.

The United States and Britain are offering aircraft, as are the Netherlands, Norway and Spain.