Myanmar's military authorities and foreign aid workers struggled on Monday to assess the damage from a devastating cyclone that killed more than 350 people and left tens of thousands homeless.
State media said 20,000 homes were destroyed on one island alone after Cyclone Nargis, a Category 3 storm packing winds of 190 km per hour, ripped through Myanmar's Irrawaddy delta on Saturday.
The death toll is likely to climb as the authorities slowly make contact with islands and villages in the delta, the rice bowl of the former Burma.
"The government is having as much trouble as anyone else in getting a full overview. Roads are not accessible and many small villages were hit and will take time to reach," Terje Skavdal, regional head of the UN office for the Coordination of Humanitarian Affairs (UNOCHA), told Reuters in Bangkok.
The movements of foreign aid workers are restricted by the military, which has ruled the former Burma for 46 years and is largely spurned by the international community due to its repressive policies.
A new policy imposed on foreign aid agencies in 2006 requires travel permits and official escorts for field trips. It also tightened rules on the transport of supplies and materials.
"That is the existing situation for international staff. The way most agencies work is they use national staff who have more freedom to move," Skavdal said "We will have a dialogue with the government to try to get access to the people affected."
The regime named Prime Minister Thein Sein to lead its relief effort in five declared disaster zones. However, the carnage left by Nargis has not derailed a May 10 referendum on a new army-drafted constitution.
"The referendum is only a few days away and the people are eagerly looking forward to voting," the junta said in a statement confirming the vote would go ahead as planned.
The charter is part of a "roadmap to democracy" meant to culminate in multiparty elections in 2010, but critics say it allows the army to retain an unacceptable degree of power.
In Yangon, many roofs were ripped off even sturdy buildings, suggesting damage would be severe in the shanty towns that lie on the outskirts of the city of 5 million people.
State television was still off the air in Yangon and clean water was becoming scarce. Most shops had sold out of candles and batteries and there was no word when power would be restored.
In one western suburb, a group of 100 monks led efforts to clear streets littered with fallen trees and debris from battered buildings, a witness said.
"The clean-up is beginning but this will take a long time. The damage around town is intense," one Western diplomat told Reuters from Yangon, where the airport reopened on Monday.
State media said 19 people had been killed in Yangon and 222 in the delta, where weather forecasters had predicted a storm surge of as much as 12 feet (3.5 metres).
Only one in four buildings were left standing in Laputta and Kyaik Lat, two towns deep in the rice-producing region.
Some 90,000 people were homeless on the island of Haingyi, around 200 km southwest of Yangon on the fringe of the delta.
United Nations disaster experts were meeting in Bangkok, the capital of neighbouring Thailand, to assess the prospects for an international relief effort.
With many buildings damaged or destroyed, plastic sheeting was a top priority to provide shelter during the rainy season.
Water purification tablets, mosquito nets and cooking equipment was needed too, Skavdal said, as well as some food aid.
Bunkered down in Naypyidaw, 240 miles to the north of Yangon, the junta's top brass has not formerly responded to an offer of international assistance.
But Myanmar's Minister of Social Welfare told U.N. officials help may be welcomed, depending on the terms, Skavdal said.
"I think it's a positive sign. As long as we are in dialogue it is good," he said.
Shunned by the West for its detention of democracy icon Aung San Suu Kyi and dismal human rights record, Myanmar has been the target of Western sanctions for years.
It receives far less foreign aid -- about $2.50 per capita -- than regional neighbours Cambodia ($47) and Laos ($63) and below the $14 average for low-income nations.
In Thailand, Nargis had weakened as it moved into western and northern parts of the country on Monday, where there were no reports of damage or casualties.