Hundreds of people are feared dead after a major earthquake hit the Caribbean nation of Haiti causing widespread destruction in the capital Port-au-Prince.
The 7.0 magnitude quake struck 15km southwest of Port-au-Prince at a depth of 10km at 4.53pm on Tuesday local time, according to the US Geological Survey website.
In the space of a minute, Haiti's suspected worst quake in 200 years wrecked the headquarters of the United Nations' stabilisation mission, Haiti's national palace, a hospital and many other buildings, the BBC reports.
Power and communications have been cut and it is feared hundreds or even thousands of people may be dead or trapped under rubble. Strong and frequent aftershocks have also been felt, and many people are refusing to sleep indoors.
About 200 people are feared missing after a hotel popular with tourists collapsed, according to an AFP report.
Haiti's ambassador to the United States Raymond Joseph described the quake as a "catastrophe of major proportions."
A "large number" of UN staff have been reported missing by the organisation following the collapse of the five-storey building.
The UN stabilisation force totals about 9000 troops and police, and was sent in to try to bring order to impoverished Haiti, which has been wracked by violence for years.
Ian Rodgers, who works for Save the Children in Port-au-Prince, says there are people clearly distressed, but cheering can also be heard as survivors are pulled from the rubble.
CNN reports the quake could be felt strongly in the eastern Cuban city of Santiago, about 400km west of Port-au-Prince.
The Pacific Tsunami Warning Center in Hawaii has lifted the local tsunami watch that had been in effect for Haiti, Cuba, Bahamas and the Dominican Republic.
Haiti is the poorest country in the western hemisphere and has a legacy of decades of violence, instability and dictatorship, the BBC reports.
It has suffered a number of recent disasters, including four hurricanes and storms in 2008 that killed hundreds.
Offers of aid
The United States Agency for International Development says it is sending disaster response teams including scores of people, search and rescue dogs and rescue equipment.
Britain said it was mobilising help and was "ready to provide whatever humanitarian assistance may be required", the BBC reports.
Canada, Australia, France and a number of Latin American nations have also said they are mobilising their aid response.
The Inter-American Development Bank says it will provide $US200,000 in immediate emergency aid.