LOUISVILLE, Kentucky: At least 25 people have been killed by flash floods in the Appalachia region of eastern Kentucky, becoming the worst flood disaster in decades.

Also, hundreds of homes and businesses have been flooded, said Kentucky Governor Andy Beshear, adding that the death toll will continue to rise.

Meanwhile, the White House has declared the floods a "major disaster" and ordered the provision of federal aid to help local rescuers.

Six children, including a one-year-old, are among the dead, as hundreds of people have been rescued by boat or helicopter.

After an aerial tour with the National Guard, Beshear said, "There are still a lot of people out there, still a lot of people unaccounted for. We are going to do our best to find them all," he added, warning that it could take weeks to find all the victims, as quoted by the BBC.

"Appalachia has had flash floods before, but not on this scale. Folks who deal with this for a living, who have been doing it for 20 years, have never seen water this high," he added.

Some areas reported more than eight inches of rain over a 24-hour period, and more rainfall is expected early next week, Beshear said, urging people to have a safety plan in place.

It is unclear exactly how many people are affected or missing, as some areas have been difficult to reach due to damaged sections on 28 state roadways, he noted, confirming that the bodies of four young siblings were among those who have been found.

The state is still recovering from the December 2021 tornadoes, the deadliest in its history, which killed more than 70 people.