"For the future of our children, we will never allow something like that to happen again."

Nato's 1999 air war on Serbia was "illegal" and failed to resolve problems in Kosovo, Serb Prime Minister Mirko Cvetkovic said yesterday in an address marking the anniversary of the bombing campaign.

"The attack on our country was illegal, contrary to international law, without a decision by the United Nations' Security Council," Mr Cvetkovic told a special sitting of his Cabinet to mark the start of the bombing campaign.

"The air strikes have not solved problems in Kosovo, and did not help to bring peace and the rule of law.

"On the contrary, they resulted in ethnic cleansing and gross violations of human rights, international standards and fresh tensions," said the Serbian Premier.

"For the future of our children, we will never allow something like that to happen again. We owe that to the victims."

Mr Cvetkovic said the Nato bombing campaign killed more than 1,000 soldiers and 2,500 civilians, including 89 children, while 12,500 people were wounded.

He put the cost of the damage at $30 billion , adding that much of the country's damaged infrastructure was yet to be repaired.

Serbian schools began commemorative events to mark the anniversary with a minute's silence yesterday.

At midday (1100 GMT), air-raid sirens sounded across the former Yugoslav republic, before church bells tolled for the victims of the 78-day air war.

Nato launched the strikes on March 24, 1999 after late President Slobodan Milosevic refused to sign up to a peace deal to end his forces' violent crackdown on the rebel Kosovo Liberation Army and the ethnic Albanian majority in the southern territory.

By the time Mr Milosevic eventually conceded 78 days later, paving the way for Nato to enter Kosovo, the civilian death toll from the bombing campaign was put at around 500 by Human Rights Watch.