By Joseph Guyler Delva and Tom Brown
PORT-AU-PRINCE (Reuters) - Thousands were feared dead in a major earthquake that destroyed the presidential palace, schools, hospitals and hillside shanties in Haiti, its leaders said Wednesday, and the United States and other nations geared up for a big relief operation.
A five-story U.N. headquarters building was demolished by Tuesday's 7.0 magnitude quake, which the U.S. Geological Survey said was the most powerful in Haiti in more than a century. Several bodies were pulled from the wreckage of the U.N. building and more than 100 staff members were missing, a spokesman said.
Prime Minister Jean-Max Bellerive told Reuters that he believed there could be "in the range of thousands of dead." Soon after, Bellerive told CNN he believed well over 100,000 people could have died.
President Rene Preval called the damage "unimaginable" and described stepping over dead bodies and hearing the cries of those trapped in the collapsed Parliament building, where the senate president was among those pinned by debris.
Destruction in the capital was "massive and broad," and tens -- if not hundreds -- of thousands of homes were destroyed, a spokesman for the U.N. mission said.
Sobbing and dazed people wandered the streets of Port-au-Prince, and voices cried out from the rubble.
"Please take me out, I am dying. I have two children with me," a woman told a Reuters journalist from under a collapsed kindergarten in the Canape-Vert area of the capital.
The presidential palace lay in ruins, its domes fallen on top of flattened walls. Preval and his wife were not inside when the quake hit.
GROUND STILL TREMBLING
The quake's epicentre was only 10 miles (16 km) from Port-au-Prince. About 4 million people live in the city and surrounding area. Many people slept outside on the ground, away from weakened walls, as aftershocks as powerful as 5.9 rattled the city throughout the night and into Wednesday.
The devastation crippled the government and the U.N. security mission that had kept order. There were no signs of organized rescue efforts, and people clawed at concrete chunks with their bare hands to try to free trapped loved ones.
Haitian Red Cross spokesman Pericles Jean-Baptiste said his organisation was overwhelmed. "There are too many people who need help ... We lack equipment, we lack body bags," he told Reuters.
Normal communications were cut off, roads were blocked by rubble and trees, electric power was interrupted and water was in short supply.
In New York, U.N. Secretary-General Ban Ki-moon said those unaccounted for at the U.N. mission headquarters included the chief of the mission, Hedi Annabi, but he could not confirm reports Annabi had died.
Brazil's army said at least 11 Brazilian members of the 9,000-strong U.N. peacekeeping mission in Haiti were killed.
The poorest country in the Western Hemisphere, Haiti is ill-equipped to respond to such a disaster, lacking heavy equipment to move debris and sufficient emergency personnel.
FLIMSY HOMES
"I am appealing to the world, especially the United States, to do what they did for us back in 2008 when four hurricanes hit Haiti," Raymond Alcide Joseph, Haiti's ambassador to Washington, said in a CNN interview.
"At that time the U.S. dispatched ... a hospital ship off the coast of Haiti. I hope that will be done again ... and help us in this dire situation that we find ourselves in."
U.S. President Barack Obama called the quake an "especially cruel and incomprehensible" tragedy and pledged swift, coordinated support to help save lives. The Pentagon was sending a nuclear-powered aircraft carrier and three amphibious ships, including one that can carry up to 2,000 Marines.
Medical aid group Doctors Without Borders said its three hospitals in Haiti were unusable and it was treating the injured at temporary shelters.
"The reality of what we are seeing is severe traumas, head wounds, crushed limbs, severe problems that cannot be dealt with with the level of medical care we currently have available with no infrastructure really to support it," said Paul McPhun, operations manager for the group's Canadian section.
The University of Miami School of Medicine sent a plane full of doctors and nurses to set up a field hospital and planned to fly a group of critically injured people to Miami for treatment Wednesday.
The United Nations said $10 million (6 million pounds) would be released immediately from the its central emergency response fund and it would organise a flash appeal to raise more money for Haiti over the next few days.
The United States, China and European states were sending reconnaissance and rescue teams, some with search dogs and heavy equipment, while other governments and aid groups offered tents, water purification units, food and telecoms teams.
NOWHERE TO GO
The quake hit at 5 p.m. (10 p.m. British time), and witnesses reported people screaming "Jesus, Jesus" running into the streets as offices, hotels, houses and shops collapsed. Experts said the quake's epicentre was very shallow at a depth of only 6.2 miles (10 km), which was likely to have magnified the destruction.
Witnesses saw homes and shanties built on hillsides tumble as the earth shook, while cars bounced off the ground. "You have thousands of people sitting in the streets with nowhere to go," said Rachmani Domersant, an operations manager with the Food for the Poor charity.
Haiti's cathedral was destroyed and media reports said the archbishop of Port-au-Prince, Monsignor Joseph Serge Miot, had been found dead in the wreckage of the archdiocese office.
(Additional reporting by Jeff Mason, Adam Entous, Patrick Worsnip, Louis Charbonneau Sophie Hardach, Raymond Colitt, Alister Bull and David Morgan; Writing by Jane Sutton and Pascal Fletcher; Editing by Vicki Allen)
