The UN warned that the category four Hurricane Matthew could cause the worst humanitarian crisis in Haiti since 2010's devastating earthquake.
The fiercest Caribbean storm in almost a decade, Hurricane Matthew, is moving onto Cuba and the US after hammering Haiti on Tuesday. The storm unleashed torrential rains and floods, killing nine people and displacing thousands of others.
The United Nations warned that the Category Four Hurricane Matthew could lead to the worst humanitarian crisis in Haiti since 2010's earthquake. The 7.0 magnitude quake killed hundreds of thousands of people and displaced more than a million.
The storm packed winds of well over 160 kilometres-per-hour (100 mph), pummelling towns, farmland and resorts. It forced hundreds of thousands of people to move to safety.
Matthew made landfall shortly after daybreak near southwestern Haiti, where it killed at least five people, with fears that the toll could climb. One person has been reported missing and 10 injured so far across the country, officials said.
The collapse of a bridge also cut off the only road linking the capital city Port-au-Prince to southern Haiti.
It has been classed as an "extremely dangerous" Category Four storm, the first time in 52 years that a Category Four storm has hit Haiti, the US National Hurricane Center said. The storm packed top winds of around 230 kilometres per hour (143 mph), it added.
"It's going to be difficult to find an alternative route," Haiti's civil protection spokesman Edgar Celestin told Agence France Presse.
The rescue effort faced difficulties as civil protection officials in Haiti said they were struggling to communicate with the south after Mathew's furious wind disrupted telephone lines.
More than 9,000 Haitians were evacuated to temporary shelters at area schools and churches, the Interior Ministry said.
Later four deaths were reported in the Dominican Republic, where officials said 200 homes were damaged.
It was unclear as to how much material damage the hurricane caused.
The eastern tip of the hurricane's next target, Cuba, was hit in the afternoon.
The storm's eye made landfall around 0000 GMT, moving towards the north around 15 kilometres per hour (9 mph), the US National Hurricane Center said.
Officials reported significant flooding and waves up to five metres (16 feet) in coastal villages in the east – but no casualties so far.
Cuban authorities evacuated some 1.3 million people.
A local resident, Roberto Gates, 63, ventured out to buy rum. "I have food for today and tomorrow, and then we'll see," he said.
At 0600 GMT, Matthew had top sustained winds of 125 mph (205 kph) and was heading north at 8 mph (13 kph) as it took aim at the Bahamas.
Forecasters reported tropical storm conditions were already spreading over the southeastern Bahamas early on Wednesday, with hurricane conditions expected there in coming hours.
Bahamas Prime Minister Perry Christie voiced concern about the potential impact on the sprawling archipelago off Florida's east coast.
"We're worried because we do not control nature," he said.
The US National Hurricane Center in Miami said winds had slightly decreased overnight as Matthew dropped from a Category 4 to a still powerful Category 3 storm.
But forecasters warned such fluctuations in intensity were to be expected and that Matthew remained a potent and dangerous storm.
The US is preparing for the approaching storm.
Georgia declared a state of emergency in 13 counties, with South Carolina saying it would begin evacuating 1.1 million people from the coast starting on Wednesday and try to get them at least 160 kilometres inland.
"It's not going to be a fast evacuation. It could take up to several hours," South Carolina Governor Nikki Haley said. "If you can leave early, do that."