Worst Floods In South Carolina 'In 1,000 Years'

At least nine people have died in South Carolina in what has been described as the worst flooding in the state in a thousand years.

Hundreds of others have been rescued after rainstorms caused by Hurricane Joaquin swept through the state.

US President Obama has declared a state of emergency.

More than a foot of rain fell overnight in the state capital Columbia, swamping hundreds of homes and businesses and threatening the water supply.

Emergency managers have issued a statewide alert telling people to remain indoors.

"Stay home. Stay off the roadways," South Carolina Emergency Management spokesperson Thom Berry said.

"Don't get on the roadways because you very likely can become part of the problem."

The message was endorsed by South Carolina Governor Nikki Haley.

"We haven't seen this level of rain in the low country in 1,000 years. That's how big it is," she said.

She added: “The water is not safe and a lot of areas across the state where you see this deep water, it’s got bacteria in it, so stay inside and don’t get in there.”

Mount Pleasant has seen 615mm of rain between 1 October and 4 October, Charleston had 517mm for the same period, while Little River saw 406mm and Myrtle Beach 403mm.

The region is forecast to see another 75mm-150mm of rain on Monday.

Emergency workers have waded into waist-deep water to help people trapped in cars.

Dozens of boats have also rescued people in flooded neighbourhoods with some being plucked from rooftops by helicopters.

Buildings and roads have crumpled and a major East Coast interstate route has been closed.

Officials in South Carolina have shut two major interstate bridges over the Broad River in Columbia.

The state Department of Transportation says at least 211 roads and 43 bridges are closed due to record levels of flooding.

Where possible the National Weather Service has urged people to move to higher ground.

"This is an extremely dangerous and life-threatening situation," it wrote in a statement issued by its Charleston office.