At least 23 people, including six children, have been killed after flash flooding in Kentucky following a series of storms.

Torrential rains have devastated the area, with its governor Andy Beshear declaring a state of emergency in six counties.

Trapped homeowners have been forced to swim to safety and others were rescued by boat as the record flash flooding hit the US state.

The deluge has swamped entire Appalachian towns and prompted a frenzied search for survivors through some of the poorest communities in America.

“We are currently experiencing one of the worst, most devastating flooding events in Kentucky’s history,” he said.

“Hundreds will lose their homes.”

He said it could take weeks to find all the victims of flash flooding.

Among the dead was an 81-year-old woman in Perry County, and the local authorities say several people are unaccounted for.

The floods marked the second major national disaster to strike Kentucky in seven months, following a swarm of tornadoes that claimed nearly 80 lives in the western part of the state in December.

“Our teams are working around the clock to help those impacted. There is still a lot of people unaccounted for, ” said governor Beshear.

He said: “This situation is ongoing. We are still in the search and rescue mode.”

Mr Beshear has appealed for federal assistance and said the damage caused could take years to repair.

The national guard and state police have been using helicopters and boats to rescue people marooned among the floodwaters, while evacuation centres have been opened in state parks.

More than 24,000 households are without power, according to the Poweroutage.us website.

Flood warnings and watches remain in effect throughout the day for the eastern half of the state as well as northeast Tennessee and western West Virginia, where more rainfall is expected to swell waterways that are already well above their flood stages, the National Weather Service (NWS) said.