Haitian President Rene Preval has said thousands of people are feared dead following a huge quake which has devastated the country's capital. Mr Preval said the UN mission chief in Haiti was among the dead. It said at least 14 other UN staff had died and 56 were injured.
The 7.0-magnitude quake, Haiti's worst in two centuries, struck on Tuesday.
Prime Minister Jean-Max Bellerive told US network CNN he believed more than 100,000 people had died. The Red Cross says up to three million people are affected.
The capital's Catholic archbishop, Monsignor Joseph Serge Miot, is also among those killed.
In his first interview since the earthquake, President Preval told the Miami Herald newspaper in the US he feared thousands of his people had died.
Describing the scene in the capital as unimaginable, he said: Parliament has collapsed. The tax office has collapsed. Schools have collapsed. Hospitals have collapsed.
There are a lot of schools that have a lot of dead people in them.”
Mr Preval later said that Hedi Annabi, the Tunisian head of the UN stabilisation mission in Haiti (Minustah), had died after the UN HQ building was destroyed.
The main prison in Port-au-Prince has also collapsed, with a UN humanitarian spokeswoman saying there had been reports of escaped inmates.
A number of nations, including the US, UK, Brazil and Venezuela, are gearing up to send aid.
Speaking in Washington, US President Barack Obama vowed unwavering support for Haiti after what he called a cruel and incomprehensible disaster.
He said he had ordered a swift, co-ordinated and aggressive effort to save lives and that the first US rescue teams would arrive later on Wednesday.
US Secretary of State Hillary Clinton announced that she was cutting short a trip to the Pacific in order to return to Washington because of the earthquake.
A US Navy aircraft carrier is expected to reach Haiti in a couple of days and a number of smaller vessels are already in the area, US defence officials said.
Rajiv Shah, of the US Agency for International Development (USAID), said US teams were on their way to Haiti with specialised rescue equipment and that some efforts were already under way on the ground.
The quake, which struck about 15km south-west of Port-au-Prince, was quickly followed by two aftershocks of 5.9 and 5.5 magnitude.
The first tremor had hit at 1653 local time (2153 GMT) on Tuesday, the US Geological Survey said. Phone lines to the country failed shortly afterwards.
UN officials said at least 14 people had died when the UN's five-storey headquarters and two smaller buildings in Port-au-Prince collapsed. Around 100 were still thought to be missing, many feared to be under the rubble.
Ten Brazilians, three Jordanians and one Haitian had been confirmed killed, a senior UN official said, adding that the number was likely to rise.
Stressing a major international relief effort would be needed, UN Secretary General Ban Ki-Moon said the UN would immediately release 10 million USD from its emergency response fund.
He said aerial reconnaissance showed Port-au-Prince had been devastated by the quake, although other areas were largely unaffected.
The airport in Port-au-Prince is operational despite the collapse of the control tower, the UN said, allowing aid to start arriving soon.
The Brazilian army, which has the biggest UN contingent in Haiti, has said a large number of its peacekeepers are missing.
China has indicated in reports in state media that eight of its peacekeepers are dead, with another 10 unaccounted for. An Argentine officer was also confirmed dead and a Uruguayan Army Colonel is missing.
A spokesman for medical charity Medecins sans Frontieres (MSF) said it was able only to offer basic care to the massive influx of survivors seeking help because all its buildings had been destroyed.
Unfortunately what we are seeing is a large number of patients in critical condition, he said. There were some reports of looting overnight.
Haiti is the poorest country in the western hemisphere and has suffered a number of recent disasters, including four hurricanes and storms in 2008 that killed hundreds.
With communications destroyed by the earthquake, it is not yet possible to confirm the extent of the destruction, although there were reports on Wednesday of many bodies piled in the streets.
Damage has also been reported in the towns of Jacmel and Carrefour, near Port-au-Prince.
Guido Cornale, a representative of the UN children's agency Unicef, in Jacmel, said it estimated more than a fifth of buildings there had been destroyed.
The Red Cross is dispatching a relief team from Geneva and the UN's World Food Programme is flying in two planes with emergency food aid.
The Inter-American Development Bank said it was immediately approving a $200,000 grant for emergency aid.
The head of the International Monetary Fund (IMF) said it would co-ordinate with other international agencies to offer help as swiftly as possible.
The World Bank also said it was sending a team to assess the damage and plan recovery. It said its offices in Port-au-Prince had been destroyed but that most staff was accounted for.
The UK said it was mobilising help and was ready to provide whatever humanitarian assistance may be required. Canada, Australia, France and a number of Latin American nations have also said they are mobilising their aid response.
Pope Benedict XVI has called for a generous response to the tragic situation in Haiti.
Top Comments
Disclaimer & comment rulesCommenting for this story is now closed.
If you have a Facebook account, become a fan and comment on our Facebook Page!