It could take weeks to find all the victims of flash flooding that killed at least 25 people in Kentucky when torrential rains swamped towns across Appalachia, the state’s governor said.

Andy Beshear said Saturday that the number of victims was likely to rise significantly as a result of record flash flooding over the past days.

“This is an ongoing natural disaster,” Mr Beshear told Fox News.

“We are still in search and rescue mode. Thankfully, the rain has stopped. But it’s going to rain more starting Sunday afternoon.”

Meanwhile, rescue crews continue the struggle to get into hard-hit areas, some of them among the poorest places in America.

Crews have made more than 1,200 rescues from helicopters and boats, the governor said.

The rain let up early Friday after parts of eastern Kentucky received between eight and 10.5 inches over 48 hours. But some waterways were not expected to crest until Saturday.

It’s the latest in a string of catastrophic deluges that have pounded parts of the US this summer, including St Louis earlier this week and again on Friday. Scientists warn climate change is making weather disasters more common.

As rainfall hammered Appalachia this week, water tumbled down hillsides and into valleys and hollows where it swelled creeks and streams coursing through small towns.

The torrent engulfed homes and businesses and trashed vehicles. Mudslides marooned some people on steep slopes.

Rescue teams backed by the National Guard used helicopters and boats to search for the missing.

Mr Beshear said Friday that at least six children were among the victims and that the total number of lives lost could more than double as rescue teams reach more areas.

President Joe Biden said in a social media post that he spoke Friday to Mr Beshear and offered the federal government’s support. Mr Biden also declared a federal disaster to direct relief money to more than a dozen Kentucky counties.

Mr Beshear predicted that it would take more than a year to fully rebuild.