World leaders pledged aid to rebuild a devastated Haiti, but on the streets of its wrecked capital quake survivors were still waiting on Sunday for the basics: food, water and medicine.
Four days after a 7.0 earthquake killed up to 200,000 people international rescue teams were still finding people alive under the rubble of collapsed buildings in Port-au-Prince.
Hundreds of thousands of hungry Haitians were desperately waiting for help, but logistical logjams kept major relief from reaching most victims, many of them sheltering in makeshift camps on streets strewn with debris and decomposing bodies.
In the absence of authority, looters swarmed over collapsed stores on the city's main commercial boulevard.
Fighting broke out between groups of looters carrying knives, ice-picks, hammers and rocks.
Many Haitians streamed out of the city on foot or jammed in cars to find food and shelter in the countryside, and flee aftershocks and violence.
Many others crowded the airport hoping to get on planes that left packed with Haitians.
Major destruction was found on Saturday in the town of Leogane, just 17 kilometres west of Port-au-Prince.
"It's the very epicentre of the earthquake, and many, many thousands are dead," said WFP spokesman David Orr.
"Nearly every house was destroyed here. The military are talking about 20,000 to 30,000 dead."
United States President Barack Obama promised help as US Secretary of State Hillary Clinton flew to Haiti, where the government gave the United States control over the congested main airport to guide aid flights from around the world.
"We're moving forward with one of the largest relief efforts in our history to save lives and deliver relief that averts an even larger catastrophe," said Mr Obama, flanked at the White House by his predecessors George Bush and Bill Clinton, who will lead a charity drive to help Haiti.
But on the streets of Port-au-Prince the distribution of aid appeared random, chaotic and minimal.
Downtown, young men could be seen carrying pistols.
There were jostling scrums for food and water as US
military helicopters swooped down to throw out boxes of water bottles and rations.
Looting has been sporadic since Tuesday's earthquake, which flattened large parts of the capital. But it appeared to widen on Saturday as people became more desperate.
The UN mission responsible for security in Haiti lost at least 40 of its members when its headquarters collapsed.
The UN said the mission's chief, Hedi Annabi of Tunisia, his deputy Luiz Carlos da Costa of Brazil and UN police commissioner in Haiti, Doug Coates of Canada, were killed.
Trucks piled with corpses have been ferrying bodies to mass graves outside the city, but thousands of bodies are still believed buried under the rubble.
Interior Minister Paul Antoine Bien-Aime said around 50,000 bodies had already been collected and the final death toll will likely be between 100,000 and 200,000.
Hillary Clinton told Haitians the United States will ensure their country emerges "stronger and better" from the disaster.
"We will be here today, tomorrow and for the time ahead," she said after meeting President Rene Preval at the airport.
Dozens of countries have sent planes with rescue teams, doctors, tents, food, medicine and other supplies, but faced a bottleneck at Port-au-Prince's small airport.
The American Red Cross said 50-bed field hospitals and water purification equipment that were rerouted to neighbouring Dominican Republic arrived by truck convoy, allowing it to start distributing water and first aid in Port-au-Prince.
Air traffic control in Port-au-Prince, hampered by damage to the airport's tower, was taken over by the US military with backup from the nuclear-powered aircraft carrier USS Carl Vinson, which arrived off Haiti on Friday.
Navy helicopters are taking water and rations ashore and ferrying injured people to a field hospital near the airport.
The Pan American Health Organization said at least eight hospitals and health centers in Port-au-Prince had collapsed or sustained damage and were unable to function.
