Yugoslavia has appealed to the International Court of Justice in a bid to stop the bombing.

Belgrade's lawyers say Operation Allied Force is tantamount to genocide.

Belgrade is claiming compensation from 10 Nato countries involved for, what it alleges is, an unlawful campaign.

Lawyer Rodoljub Etinski told the court in The Hague: "The acts of bombing against Yugoslavia are not just illegal acts, they constitute a violation of human rights and the perpetration of the crime of genocide."

"By killing people, by murdering children ... by destroying a whole nation, they want to protect a part of that population, one of its numerous ethnic minorities."

But shortly before the hearing began, Nato spokesman Jamie Shea called the legal move "particularly cynical". He said Yugoslav President Milosevic was responsible for the worst violations of human rights for half a century.

Mr Etinski told the court in the Hague that Yugoslavia's crackdown in Kosovo was aimed at suppressing terrorism and that the allies had no right to intervene in an internal conflict.

Joshua Rozenberg: "Serbia says Nato is guilty of genocide"

He told the court that Nato was using internationally banned weapons - cluster bombs and bombs containing depleted uranium - and was arming and training the Kosovo Liberation Army, which he described as a terrorist group.

The Belgrade Government wants the court to tell the United States, the United Kingdom, and other leading Nato countries to stop the airstrikes and pay Yugoslavia compensation.

Legal Affairs Correspondent Joshua Rozenberg: "Court heard Nato breached UN Charter"

The Serbs say that actions taken by the 10 Nato members represent "a gross violation" of their obligation not to use force against another state.

Ian Brownlie, a British professor of public international law who is on the Yugoslav legal team, told the court: "There is no general humanitarian purpose to these acts.

"The pattern of targets indicate political purposes unrelated to humanitarian reasons."

Geneva Convention

Yugoslavia says Nato has broken the United Nations Charter by taking enforcement action without authorisation from the Security Council.

Belgrade also accuses the alliance of breaking the 1949 Geneva Convention on the protection of civilians in time of war. Finally, Yugoslavia accuses Nato of genocide.

BBC Legal Affairs Correspondent Joshua Rozenberg says that the genocide allegation against Nato is perhaps the most striking.

It argues that Nato countries are in breach of their obligation not to deliberately inflict on a national group conditions of life calculated to bring about its physical destruction, in whole or in part.

Defending Nato

Yugoslavia is asking the court to make a temporary ruling ordering the Nato countries to stop the campaign.

The 10 Nato nations named by Yugoslavia have each been given one hour to put their cases.

Belgium, Canada and France were the first to outline their cases, giving a vigorous defence of Nato action.

They said that a court order stopping the bombing would turn reality on its head.

Canada's representative Philippe Kirsch said siad: "Provisional measures [ordering a halt to strikes] would not avoid irreparable damage, it would cause irreparable damage.

Belgium's representative Rusen Ergec said: "I would defy the Federal Republic of Yugoslavia to submit any evidence of any such intention to bring about the destruction of an ethnic, religious or national group."

And Ronny Abraham, a French Foreign Ministry official, said: "Yugoslavia is using the court as a political forum."

Before the hearing the US, which is due to put its case on Tuesday, described the legal action as an "absurdity" and "an obvious attempt to divert attention from the atrocities" perpetrated by the Belgrade regime.

Yugoslav demands

The Federal Republic of Yugoslavia wants the court to declare that:

• Nato countries have wrongly intervened in the affairs of another state by supporting the Kosovo Liberation Army.

• Nato countries have unlawfully attacked civilians and their property.

• Nato countries are in breach of their obligation not to commit any act of hostility against historical monuments, works of art or places of worship.

• By using cluster bombs, the Nato countries have broken their duty not to use weapons calculated to cause unnecessary suffering.

• By bombing oil refineries and chemical plants, the Nato countries have acted in breach of their obligation not to cause considerable environmental damage.

• By using weapons containing depleted uranium, the Nato countries have acted in breach of their obligation not to use prohibited weapons and not to cause far-reaching health and environmental damage.

• By killing civilians, and by destroying enterprises, communications, health and cultural institutions, the Nato countries failed to meet their obligations to respect basic human rights.

• By destroying bridges on international rivers, the Nato countries have acted in breach of their obligation to respect freedom of navigation.