Matthew, the first major hurricane threatening a direct hit on the United States in more than 10 years, has blasted the Bahamas as it heads for Florida after killing at least 339 people in the Caribbean, mostly in Haiti, ABC News reported on Friday.

Roadways in Florida, Georgia and North and South Carolina were jammed and gas stations and food stores ran out of supplies as the storm approached, bringing storm surges, heavy rain and sustained winds that accelerated overnight to about 220 kilometres per hour.

Matthew — which killed at least 339 people and displaced thousands, mostly in southern Haiti — has since been upgraded from a category three to a category four storm while en route to Florida's Atlantic coast.

Landfall was expected there on Thursday night (local time), the US National Hurricane Centre said.

The Centre extended its hurricane warning area farther north into Georgia, and more than 12 million US residents were under hurricane watches and warnings, according to the Weather Channel.

"Everyone in our state must prepare now for a direct hit," Florida Governor Rick Scott said at a news conference in Tallahassee.

Source: MENA