Hundreds of thousands of people in the Philippines are still in desperate need of help, almost a week after Typhoon Haiyan hit.
Emergency supplies of food, water and medical kits are ready to be delivered but they remain frustratingly out of the survivors' reach.
Valerie Amos, the UN humanitarian chief, says the situation will get better, but Al Jazeera's Marga Ortigas, reporting from Tacloban on Thursday, said that for many residents, the only option was to leave.
Desperate residents are clamouring to leave the hard-hit coastal city, jostling and begging for seats on scarce flights. Philippines Airlines said it was operating six flights a day, each with 75 seats.
The UN estimates that 10,000 people may have died in Tacloban alone, where five-metre waves flattened nearly everything in their path. President Benigno Aquino, however, says the death toll is no more than 2,500 people.
Describing Tacloban, the provincial capital of Leyte, as a city "absolutely devastated", Amos told Al Jazeera: "The national authorities, the local authorities, the United Nations, our partners, and both national and international NGOs are all pulling together. They are trying to make sure the supplies are coming in.
“We've had some significant challenges over the first few days. The scale of this disaster ... was essentially like a tsunami.
"Debris has prevented the roads from being passable. For example, even though we had teams arrive on the road on Saturday, the day after the typhoon, it was impossible to get into the city by road, even though it's only a few kilometres away.
Amos said: “We are also challenged ... because there is no fuel [which means] there are very few trucks on the ground. So we need to find a a way to get those goods to Tacloban."
Jericho Petilla, Philippine energy secretary, has said it may take six weeks before the first typhoon-hit towns get their electric power back.
Speaking at Cebu airport on Wednesday night, Petilla said many transmission lines had been toppled and power plants damaged by Haiyan.
He said that in Tacloban, order needed to be restored "because if there's no peace and order, it's hard to reinstall the power posts".
He said army troops had fired shots on Wednesday to drive away a group of armed men who approached a power transmission sub-station in Leyte.
The unidentified men fired back then fled. Nobody was hurt.
Overwhelmed by numbers
Al Jazeera's Wayne Hay, reporting from Tacloban on Thursday, said doctors were struggling to cope with the rising number of patients and dwindling medical supplies.
Panic is mounting in the country, with minimal food and medical supplies reaching areas worst hit by the storm, reports of civil order breaking down and the number of unburied dead threatening the health of survivors.
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The World Health Organisation said there were significant injuries that needed to be dealt with, even as medics worked to prevent outbreaks of disease caused by cramped living conditions and dirty drinking water.
It cautioned regular health needs also had to be met, including the 12,000 babies expected to be born this month to the more than 11.3 million people affected.
Overwhelmed and under-resourced rescue workers have been unable to provide food, water, medicines, shelter and other relief supplies to some of the 673,000 made homeless, and desperation has been growing across the disaster zones.
"People are desperate because they have nothing in Tacloban," Marco Boasso of the International Organisation for Migration said.
Hundreds of soldiers and police patrolled the streets and manned checkpoints in Tacloban on Wednesday to try to prevent pillaging.
Rene Almendras, Philippine cabinet secretary, said the government had been overwhelmed by the sheer number of victims that needed to be buried.