The death toll in the disastrous earthquake in Haiti has crossed 50,000 and it may touch the 200,000 figure, a Haitian minister said on Saturday.
"We have already collected around 50,000 dead bodies," Paul Antoine Bien-Aime, Haiti's interior minister told Reuters. "We anticipate there will be between 100,000 and 200,000 dead in total, although we will never know the exact number."
Around 40,000 bodies have been buried in mass graves. Although doctors, rescue teams and supplies had been flying into the Haitian capital, Port au Prince, a series of bottlenecks meant aid was not getting to those who needed it most.
The sound of gunfire echoed around Port au Prince as looters fought over scarce food supplies, hijacked vehicles and raided a UN warehouse where 15,000 tons of food had been stockpiled.
Even the most stoic Haitians began to express frustration at the continued lack of help on the fourth day of their ordeal, and in one part of the capital corpses were piled up to build roadblocks in protest at the delays.
Haiti's shell-shocked government gave the United States control over its main airport to bring order to aid flights from around the world and speed relief to the impoverished Caribbean nation.
Trucks piled with corpses have been carrying bodies to hurriedly excavated mass graves outside the city but thousands of bodies still are believed buried under rubble.
The problem has been worsened by the complete destruction of Port-au-Prince's main prison, where almost all of the 4,000 inmates survived the earthquake and are now roaming the streets.
Rescuers have been told to stop work when it gets dark because of fears they will be attacked.
"Our biggest problem is security," said Delfin Antonio Rodriguez, rescue commander for the Dominican Republic. "Yesterday they tried to hijack some of our trucks. Today we were barely able to work in some places because of that. There's looting and people with guns out there, because this country is very poor and people are desperate."
Shaul Schwarz, a photographer for TIME magazine, said he saw at least two roadblocks formed with bodies of earthquake victims and rocks.
"They are starting to block the roads with bodies," he said. "It's getting ugly out there. People are fed up with getting no help."
Pierre Jackson, who is desperate for medical help for his mother and sister who both have crushed legs, said: "We've been out here waiting for three days and three nights but nothing has been done for us. What should we do?"
The situation improved with the arrival of the American aircraft carrier USS Carl Vinson, with 19 helicopters on board, which will be used to transport supplies by air. The US is also sending more than 10,000 soldiers and marines to keep the peace.
Charities have managed to set up several field hospitals, and 17 search and rescue teams were picking through the rubble of collapsed buildings with sniffer dogs, pausing every so often to wait for aftershocks to pass.
Most Haitians, however, are still having to use their bare hands to search for survivors.
"We hear on the radio that rescue teams are coming from the outside but nothing is coming," said Jean-Baptiste Lafontin Wilfried, as he helped dig through the remains of an office building. "We only have our fingers to look for survivors."
The World Food Programme (WFP) said it was drawing up plans to feed two million people for a month.
Emila Casella, of the WFP, said: "The physical destruction is so great that physically getting from point A to B with the supplies is not an easy task. Pictures can get out instantly ... and that's important because the world needs to know. But getting physically tons and tons of equipment and food and water is not as instant as Twitter or Skype or 24-hour television news."
The charity Medecins Sans Frontieres said "thousands" of people in Haiti were waiting for surgical treatment. The UN was looking at the possibility of using the national soccer stadium in Port au Prince as a base for a giant field hospital.
Meanwhile, with bloated corpses posing an increasing risk to public health, mass graves were being dug to get the bodies off the streets.
Aid workers from as far afield as China, France, Iceland and Venezuela are among those already deployed on the ground in Haiti.
Some of the wounded, including Spain's ambassador to Haiti and some staff from the US embassy, were taken to the nearby US naval base at Guantánamo Bay, Cuba – site of the controversial prison camp for terrorism suspects – for medical treatment.
Liony Batista, project manager of the charity Food for the Poor, said: "I don't think that a word has been invented for what is happening in Haiti. It is a total disaster."
US helicopters were ready aboard the aircraft carrier USS Carl Vinson, but there's a problem: after a day of frantic aid runs there is simply nothing left to deliver.
Aboard the warship some 3,500 US military personnel have been coordinating the flights of 19 US helicopters carrying aid since early morning. Visible from the ship is Haiti's scarred capital Port-au-Prince.
In less than 12 hours, helicopters from the USS Carl Vinson made some 20 trips to scout the ravaged landscape and deliver items that were originally intended for the ship's crew.
Among the supplies dropped off were thousands of bottles of water and energy drinks, 8,000 sheets and hundreds of camp beds. Dozens of hospital beds have been arranged on board the ship to accommodate those injured in the quake, including a US citizen evacuated from the US embassy in Port-au-Prince.
The take off and landing space offered by aircraft carriers are crucial for the international aid effort, which has struggled to get in relief via Port-au-Prince's single-runway airport.
The relief work also faces logistical and coordination challenges, according to Rear Admiral Ted Branch, the most senior military official aboard the USS Carl Vinson.
Secretary of State Hillary Clinton is heading to Haiti to inspect earthquake damage and discuss how to speed up humanitarian aid and further shape the recovery effort.
Dr. Rajiv Shah, the White House's designated coordinator of the U.S. relief effort, told reporters the main focus of U.S. efforts was still on recovering trapped survivors. Shah was to accompany Clinton to Haiti.
