Nearly half of the Iraqi population may be left without food or water in the aftermath of a war against the country, the United Nations has warned in a new report.

UN estimates

16 million or 60% of Iraqis dependent on government rations Two million refugees expected (half inside Iraq) 500,000 people will need medical treatment in early stages of war Two million children and one million pregnant or lactating women will need immediate "therapeutic feeding"

The document presented to the Security Council by UN Secretary General Kofi Annan added that the international community would need to contribute a further $80m to help alleviate the potential crisis.

And it noted that the shortages inflicted by conflict would come as a double blow in a nation which already faces severe food distribution problems as a result of sanctions.

Mr Annan was briefing ambassadors on preparations for humanitarian relief in Iraq, but officials were keen to stress that he still does not think war is inevitable.

Mass departure

A high proportion of Iraq's 23 million people currently depend on food rations provided by the Baghdad government.

If central distribution were disrupted - as it would be in a war - the UN estimates that these people would, at best, have six weeks worth of rations before food runs out.

Much of the country is already dependent on government food rations

Military action is also likely to destroy much of the country's sanitation infrastructure, leaving 50% of the population without access to drinking water.

The UN refugee agency, the UNHCR, has meanwhile estimated that some 60,000 Iraqis may flee the country.

The agency believes half the total would probably head for Iran, while the remainder would make their way to Turkey, Syria and Jordan.

'Misconstrued'

UN officials say food, medical supplies, shelter material and staff are being moved to the countries neighbouring Iraq.

But many officials have been concerned that if contingency planning goes too far, it could appear as if the UN believes war in Iraq is inevitable.

"Contingency planning should not be misconstrued," said the UN's emergency relief co-ordinator Kenzo Oshima. "It is simply a matter of prudence."

"Nevertheless we must recognise that conflict might occur and cause terrible suffering to the Iraqi people."

Donor countries have pledged nearly $40m to help deal with any humanitarian crisis, but Mr Oshima said they needed to give much more - estimating that at least $120m was needed.