Casualties from Saturday’s cyclone continues to rise in Burma, as international agencies are pushing to gain access for a massive aid operation there.
Burma officials say 15,000 people died in the disaster, and many more are missing. The cyclone Nargis brought winds reaching 190km/h (120mph).
Some areas are still cut-off, and hundreds of thousands of people are said to still be without clean water and shelter.
Leaders of the country say they will accept external help, which reflects the scale of the disaster.
In areas worst-hit by the cyclone, including the former capital Rangoon and the Irrawaddy Delta, a referendum on a new constitution will be postponed to 24 May, said state television on Tuesday.
The vote will proceed as planned in the rest of the country, on 10 May.
Chris Raye, the director for the World Food Programme in Burma, said information was still emerging about the destruction in the Irrawady Delta, but that it was clear it was on a very large scale.
From Rangoon, Mr Raye told the BBC World Service’s World Today programme : “we have a major humanitarian catastrophe in our hands. The numbers of people in need are still to be determined, but I’m sure we’re talking of hundreds and thousands.”
“The concern that we have is in respect to shelter, water and sanitation. Those are the acute needs which need to be fulfilled as a matter of urgency, and to be able to address those is a prerequisite to ensuring that the humanitarian situation does not deteriorate. ”
Burma country director for Save the Children, Andrew Kirkwood, said there were positive signs from the Burmese authorities, who have traditionally been suspicious of aid agencies, limiting their activities.
“Every indication is that everyone realises that this is an unprecedented event in Myanmar’s [Burma’s] history and the government is much more open to international assistance than it has ever been.”
To Mr Kirkwood, responding to the devastation would be a major logistical feat, requiring boats and trucks.
Weak government response
The storm caused a sea surge that smashed through towns and villages in the low-lying Irrawaddy Delta region.
“Those areas in the southern part of the Delta – Bogalay, Laputta and Gyapor – were very severely affected, particularly by the storm surge” said Mr Raye.
“And a storm surge in a low-lying area such as that, coupled with very high winds, clearly has served to flatten large areas of that part of the delta, and of course taken villages and villagers with it.”
People accross the region have been left homeless by the storm that destroyed roads, downed power lines and flattened houses.
“Reports are coming out of the delta coast, particularly the Irrawaddy region, that in some villages up to 95% of houses have been destroyed” said Matthew Cochrane of the International Red Cross.
And more people are at risk because in the wake of the storm prices of food, fuel and basic necessities have also risen dramatically.
The UN would do “whatever [necessary] to provide urgent humanitarian assistance”, said Secretary-General Ban Ki-moon.
India is sending two naval vessels, and a shipment of aid from Thailand is due to arrive on Tuesday.
The US has also offered to increase aid offered to Burma, if the country agrees to allow a US team access to assess the situation.
Laura Bush (photo), who takes a special interest in Burma, urged the country to accept $250,000 (£126,000) already allocated for emergency aid, and said more would be available, if the team was allowed into the country.
US First Lady also accused the Burmese authorities of failing in order to give a “timely warning” concerning the approaching storm.
Residents complained in Rangoon, saying the government response to the disaster has been weak.
One grocery store owner told the Associated Press news agency that“the government misled people”. “They could have warned us about the severity of the coming cyclone so we could be better prepared.”