A glimmer of hope emerged from the horror of the Haiti earthquake today as a two-year-old boy was pulled alive from his collapsed home.

Dirty and teary-eyed, Redjeson Hausteen Claude appeared to smile at his ecstatic mother as he was carried from the rubble by a Spanish rescue team.

But elsewhere there was little hope. Another child, nine-year-old Haryssa Keem Clerge, had been trapped inside a basement and had been heard begging to be rescued as neighbours clawed at the rubble of one of hundreds of toppled structures teetering on the side of a ravine.

Just hours later her lifeless body was finally pulled from the mass of concrete and twisted metal. Wrapped in a green bath towel, it was placed inside a loose desk drawer. With nowhere to take it, the body was then left on the hood of a battered Isuzu Trooper.

"There are no police, no anybody," said the child's despairing godmother, Kettely Clerge. A day earlier, the little girl's mother, Lauranie Jean, was pulled from the rubble of the same house. She lay moaning inside a tent Thursday as volunteers rubbed ointment into open wounds on her sides.

The death toll from the devastating earthquake in Haiti may be as high as 50,000 to 100,000 people, the Pan American Health Organization said on Friday. Jon Andrus of PAHO, the Americas arm of the World Health organization, told a news briefing: "A variety of sources are estimating the numbers (at) between 50,000 and 100,000."

Meanwhile aid workers hoping to distribute food, water and other supplies to a shattered Port-au-Prince are warning their efforts may need more security today as Haitians grow increasingly desperate and impatient for help.

Hundreds of US paratroopers arrived overnight to back up the relief effort. Hard-pressed government workers, meanwhile, were burying thousands of bodies in mass graves. The Red Cross estimates 45,000 to 50,000 people were killed in Tuesday's cataclysmic earthquake.

More and more today, the focus fell on the daunting challenge of getting food and water to millions of survivors. United Nations peacekeepers patrolling the capital said people's anger is rising that aid hasn't been distributed quickly, and the Brazilian military warned aid convoys to add security to guard against looting.

"Unfortunately, they're slowly getting more angry and impatient," said David Wimhurst, spokesman for the Brazilian-commanded UN peacekeeping mission. "I fear, we're all aware that the situation is getting more tense as the poorest people who need so much are waiting for deliveries. I think tempers might be frayed."

The UN World Food Programme reported today that its warehouses in the Haitian capital had been looted since the devastating quake. It later announced that most of the stocks taken from the four warehouses had been recovered.

A spokeswoman for the Rome-based agency, Emilia Casella, noted that regular food stores in the city also had been emptied by looters. Casella said the WFP was preparing shipments of enough ready-to-eat meals to feed two million Haitians for a month.

The UN Secretary-General Ban Ki-moon said today he would soon travel to Haiti "both to show solidarity with the people of Haiti and our UN staff and to assess the situation for myself".

The latest confirmed death toll among UN personnel in Haiti is 37, with around 330 UN personnel missing or unaccounted for out of roughly 12,000 in Haiti.

Ban said the United Nations was focusing on more than its own personnel and was trying to coordinate rescue efforts from the Port-au-Prince airport.

More than 300 troops of the US 82nd Airborne Division arrived at the Port au Prince airport overnight and others have arrived in nearby waters on the aircraft carrier USS Carl Vinson, Lt. Gen. Ken Keen told ABC's "Good Morning America."

"We have much more support on the way. Our priority is getting relief out to the needy people," he said.

About 5,500 US soldiers and Marines are expected to be in Haiti by Monday. Their efforts will include providing security, White House spokesman Robert Gibbs said.

Hundreds of bodies were stacked outside the city morgue, and limbs of the dead protruded from the rubble of crushed schools and homes. A few workers were able to free people who had been trapped under the rubble for days, including a New Jersey woman, Sarla Chand, freed by French firefighters yesterday from the collapsed Montana Hotel. But others attended to the grim task of using bulldozers to transport loads of bodies.

Haitian President Rene Preval told The Miami Herald that over a 20-hour period government crews had removed 7,000 corpses from the streets and morgues and buried them in mass graves.

For the long-suffering people of Haiti, the western hemisphere's poorest nation, shock was giving way to despair.

"We need food. The people are suffering. 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."

From Europe, Asia and the Americas, more than 20 governments, the UN and private aid groups were sending plane loads of high-energy biscuits and other food, tons of water, tents, blankets, water-purification gear, heavy equipment for removing debris, helicopters and other transport. Hundreds of search-and-rescue, medical and other specialists also headed to Haiti.

The WFP began organising distribution centres for food and water yesterday, said Kim Bolduc, acting chief of the large UN.mission in this desperately poor country. She said that "the risk of having social unrest very soon" made it important to move quickly.

Governments and government agencies have pledged about $400m worth of aid, including $100m from the United States.

But into the third day following the 7.0-magnitude quake, the global helping hand was slowed by a damaged seaport and an airport that turned away civilian aid planes for eight hours yesterday because of a lack of space and fuel.

Aid workers have been blocked by debris on inadequate roads and by survivors gathered in the open out of fear of aftershocks and re-entering unstable buildings.

"The physical destruction is so great that physically getting from point A to B with the supplies is not an easy task," Casella, the WFP spokeswoman in Geneva, said at a news conference.

Across the sprawling, hilly city, people milled about in open areas, hopeful for help, sometimes setting up camps amid piles of salvaged goods, including food scavenged from the rubble.

Small groups could be seen burying dead by roadsides. Other dust-covered bodies were being dragged down streets, toward hospitals where relatives hoped to leave them. Countless dead remained unburied, some in piles. Outside one pharmacy, the body of a woman was covered by a sheet, a small bundle atop her, a tiny foot poking from its covering.

Aid worker Fevil Dubien said some people were almost fighting over the water he distributed from a truck in a northern Port-au-Prince neighbourhood.

Elsewhere, about 50 Haitians yearning for food and water rushed toward two employees wearing "Food For The Poor" T-shirts as they entered the international agency's damaged building.

"We heard a commotion at the door, knocking at it, trying to get in," said project manager Liony Batista. "'What's going on? Are you giving us some food?' We said, 'Uh-oh.' You never know when people are going over the edge."

Batista said he and others tried to calm the crowd, which eventually dispersed after being told food hadn't yet arrived.

"We're not trying to run away from what we do," Batista said, adding that coordinating aid has been a challenge. "People looked desperate, people looked hungry, people looked lost."

Engineers from the UN mission have begun clearing some main roads, and law-and-order duties have fallen completely to the mission's 3,000 international troops and police.

Wimhurst, the mission spokesman, said Haitian police "are not visible at all," no doubt because many had to deal with lost homes and family members. The first US military units to arrive took on a coordinating role at the airport.

Batista, the Food For The Poor project manager, went back to the Dominican Republic late yesterday and awaited the arrival of 100 shipping containers loaded with rice, canned goods and building supplies.