The death toll from Haiti's earthquake climbed to as high as an estimated 140,000, as logistical bottlenecks delayed aid and stoked looting by survivors desperate for food and water.
A flotilla of ships anchored offshore while aircraft circled overhead, but only a trickle of supplies and emergency teams made it onto the shattered streets of Port-au-Prince, where the desperation was turning into violence.
Groups of men with machetes roved the ruins seeking supplies of food or water; others used corpses as roadblocks, a macabre sign that the capital had reached breaking point after four days of apocalyptic scenes. "They are scavenging everything. What can you do?" Michel Legros, 53, told AP as he waited for help to search for seven of relatives buried in his collapsed house.
Aramick Louis, secretary of state for public safety, told Reuters the death toll had exceeded 140,000. "We have buried 40,000 people. We think there are 100,000 more on top of that."
The Pan American Health Organization, the Americas arm of the World Health Organization, estimated the deaths from Tuesday's magnitude 7 quake at between 50,000 and 100,000, but said that was a "huge guess". Earlier this week the Red Cross estimated up to 50,000. A British woman, UN worker Ann Barnes, 59, remains missing after the building in which she was collapsed in the earthquake.
The UN secretary-general, Ban Ki-moon, estimated that in the worst areas 50% of buildings were damaged or destroyed, leaving 3m people without access to food, water, shelter and electricity. Ban Ki-moon said he would arrive in Haiti "very soon".
More than 25 rescue teams are now deployed at schools, hotels, hospitals and larger buildings, with 13 more on their way, according to the UN. No further field hospitals were required, but surgeons and medicines were badly needed.
Teams dug out dozens of survivors, but any joy was fleeting amid the sight and stench of thousands of corpses decomposing under a tropical sun.
Graves, some with more than a hundred bodies, were dug in rural areas just outside the capital, while in the shantytown of Carrefour local authories said more than 2,000 corpses were burned. The WHO recommended corpses be treated with chemicals and interred in open ditches, giving relatives a chance to identify them, rather than mass graves. "The scale of this disaster has overwhelmed all capacities," said Paul Garwood, a WHO spokesman. "There's an urgent need to get more and more body bags into the area so that we can properly handle these bodies."
In Washington, Barack Obama said that help was on its way: "I want the people of Haiti to know we'll do what it takes to save lives and to help them get back on their feet," said the US president. "The scale of the devastation is extraordinary ... and the losses are heartbreaking."
His secretary of state, Hillary Clinton, was due to arrive in Port-au-Prince today for talks with President René Préval. Clinton said details of her trip were being worked out but that she planned to bring relief supplies as well as helping to evacuate some Americans.
Hospitals and clinics are either destroyed or overwhelmed. Many of the wounded streamed into the neighbouring Dominican Republic seeking treatment. "There have been more than 500 today; so, so many," anaesthesiologist Gilberto Rojas told the New York Daily News. "We have been doing so many amputations, seeing so many people with abdominal trauma."
President Préval and the prime minister, Jean-Max Bellerive, were said to be coordinating the government response from the judicial police HQ near the airport but on the streets the state was again absent, with virtually no sign of police or emergency crews. The 9,000-strong UN peacekeeping force seemed stunned by the disaster and its own losses.
Whether it wanted to or not, the United States was rapidly taking ownership. Obama has pledged an initial $100m and enlisted his predecessors, Bill Clinton and George W Bush, to help raise more.
Last night Haiti's government agreed to grant temporary control of the airport to the US to speed relief work, thestate department said. A vanguard of 300 paratroopers arrived overnight, and 10,000 more troops will be in Haiti and offshore by Monday, said Admiral Mike Mullen.
Helicopters from the carrier USS Carl Vinson ferried supplies ashore but off-loading was fraught because the port and airport were damaged and congested. The navy said it would serve as a "floating airport". Military planners hesitated to drop food and water packages from the air because it could lead to rioting.
"The key is to get the food and the water in there as quickly as possible, so people don't in their desperation turn to violence or lead to the security situation deteriorating," said the defence secretary, Robert Gates. Cuba gave the US permission to fly over its airspace, saving 90 minutes.
Across Port-au-Prince the refrain was the same. "My neighbours and friends are suffering," said Sylvain Angerlotte, 22. "We don't have money. We don't have nothing to eat. We need pure water."
UN peacekeepers protected convoys, while aid workers reported scuffles as people scrambled for supplies of water and energy biscuits. "We're sending our police into areas where bandits are starting to operate," said Louis, the public safety secretary of state. "Some people are robbing, are stealing. That is wrong. Our message to everyone is to stay calm."
Shops have been stripped, but UN food warehouses, contrary to earlier reports, were not looted. "The food is there," said a spokeswoman, Emilia Casella. They are working on getting a peacekeeper contingent to protect the warehouses. Some 6,000 tons of food and other supplies were due to be handed out.
The UN said that it was considering converting the national football stadium into a field hospital, and setting up collective kitchens for the homeless.
Jan Egerland, a former UN humanitarian chief, said: "We're in a very classic development. Days three, four and five are the most frustrating. Everybody knows the whole world is mobilising, and everyone has heard the promises. But it takes time to reach the beneficiaries. The infrastructure has either gone or is totally clogged up," he told the BBC.From his exile in South Africa, Haiti's former president, Jean Bertrand Aristide, said that he and his wife were ready to return.
"We are ready to leave today, tomorrow, at any time, to join the people of Haiti. To share their suffering to rebuild the country, moving from poverty with dignity," he told reporters, tears streaming down his face.
