The United Nations' humanitarian chief pledged Saturday to work through logistical bottlenecks which have thus far slowed relief efforts in Haiti, where millions of quake survivors need food, water and medical help.

Recent developments:

  • U.S. to deliver 600,000 daily rations of food Saturday evening
  • At least 100,000 dead: Haitian prime minister
  • U.S. Secretary of State Hillary Clinton arrives
  • UN Haiti mission chief Hedi Annabi found dead

For the fourth day, the country's main airport has been rammed with aircraft attempting to deliver supplies. Meanwhile, relief workers rushing to the decimated capital of Port-au-Prince have been slowed by clogged roads.

Still, there were signs that aid was finally getting through to the neediest on Saturday evening, even as aftershocks rumbled across the shattered capital.

"What we're trying to do is scale up our efforts as fast as we can," said UN Emergency Relief Co-ordinator John Holmes, in an interview with CTV News Channel.

Holmes said that workers have been successful in reaching many of the needy, but as the scope of the relief effort expands, so does the magnitude of the catastrophe.

"What you have to understand is the infrastructure of the capital ... is more or less completely collapsed," Holmes said, speaking from New York.

"Unfortunately, there's no magic solution."

Incoming supplies

While some agencies had complained that back-ups at the airport have hampered the delivery of aid, others said the co-ordination was improving and relief supplies were beginning to flow.

By Saturday evening, the local government had established 14 aid distribution points, and the U.S. was looking to create more.

The U.S. had held off delivering food to several large groups until enough was available for everyone.

But for many in the hot, crowded capital, food, water and medicine couldn't arrive soon enough.

"People are so desperate for food that they are going crazy," said local accountant Henry Ounche, who was waiting with hundreds of others as a U.S. helicopter filled with supplies tried to land in Port-au-Prince.

Elsewhere, young men ripped the pipes from shattered buildings in the hopes of finding even a few drops of water.

"This is very, very bad, but I am too thirsty," said a man named Pierre Louis Delmar.

The 7.0-magnitude quake struck Tuesday afternoon, cutting a swath of destruction that levelled buildings and left hundreds of thousands of people homeless.

The International Federation of the Red Cross on Saturday launched a convoy carrying a "massive amount of aid," which is making its way into Haiti through the Dominican Republic on Saturday.

According to the World Health Organization, eight health-care facilities in Port-au-Prince were destroyed by the earthquake, making delivering medical treatment extremely difficult.

Magalie Boyer of World Vision told the Associated Press that the city's largest hospital, l'Hopital General, was open but swamped with the dead and injured Saturday.

As well, the Canape Vert hospital had partially collapsed but was still accepting some patients.

Widespread destruction

Though some agencies have been transitioning from searching the rubble for survivors to handing out supplies, the UN's Holmes said survivors are still being found amidst the collapsed concrete of the capital.

"We'll go on with that work as long as there is any hope of finding people alive," he said.

In one case, a 29-year-old woman was pulled from the rubble after being trapped for 97 hours.

While an official count of the dead has thus far been impossible, The Pan American Health Organization said 50,000 to 100,000 died in the quake.

Haitian Prime Minister Jean-Max Bellerive told The Associated Press that a final death toll of 100,000 dead would "seem to be the minimum."

Earlier in the week, the Red Cross had estimated that up to 50,000 died in the quake.

Haitian President Rene Preval, who met with Hillary Clinton Saturday, called the quake's aftermath "an extremely difficult situation. We must keep our cool to do co-ordination and not to throw accusations at each other."

Clinton pledged continued support for the country and said the U.S. would be "as responsive as we need to be."

Comparing the quake to previous disasters, UN humanitarian official Elisabeth Byrs said the quake was the most difficult situation the organization had handled.

She said it was even worse than the 2004 Asian tsunami, because much of the infrastructure is damaged. The UN's headquarters was mostly destroyed in the quake.

Highlighting the mass destruction, top officials like Hedi Annabi, the UN's mission chief in Haiti, have been found dead. His acting chief of police, RCMP Supt. Doug Coates, was also declared dead Saturday. Coates is among eight Canadians who have been declared dead so far.

Struggle on the streets

The continued desperation in Port-au-Prince has raised tension in the city, as unclaimed bodies continue to be piled on the streets, while workers bury others in mass graves.

About 20,000 bodies have been driven out of town to be burned, the Haitian government said.

For the past few days, residents have painted toothpaste around their nostrils and to cut the smell of decaying bodies.

Evidence of the frayed nerves could be seen when a fight broke out as hundreds of people waited for U.S. choppers to land with much-needed supplies at an impromptu supply base which was set-up at a golf course in the city's more affluent zone.

However, as the fight expanded, the helicopter pilots decided to take off again, deeming it was too dangerous to stay. The crowd was left with nothing.

Scuffles have also been reported in other areas as people scramble for supplies.

While UN peacekeepers have warned that aid convoys should add security when entering Port-au-Prince to prevent looting, other aid agencies say they haven't experienced widespread theft or interference.

"So far, we've never had any incidents" said Jean Pierre Taschereau, from the Canadian Red Cross.

He told CTV News Channel from Port-au-Prince that some of the organization's vehicles have come across blockades, but have been let through quickly because the Red Cross symbolizes "neutral, humanitarian" aid.

Still, roving looters have been seen on the streets armed with machetes and robbers reportedly shot one man whose body was left on the street. A water delivery truck driver said he was attacked in one of the city's slums.

With files from The Associated Press