At least 24 dead and more than 20 children missing from camp in flooding

At least 24 people have been killed in the US state of Texas after heavy rain caused flash flooding, according to local media reports.

Officials have also said 23 children are missing from a girls' camp in Texas. As much as 10 inches (25 centimetres) of heavy rain fell in just a few hours overnight in central Kerr County, causing flash flooding of the Guadalupe River.

An official in the city of Kerville told reporters the flooding struck before dawn "over a very short period of time that could not be predicted, even with the radar". Judge Rob Kelly, the chief elected official in the county, confirmed fatalities from the flooding and dozens of water rescues so far.

The judge told reporters at a news conference that "most" of the bodies are yet to be identified. "We're trying to get the identity of these folks, but we don't have it yet," he said.

As of Friday night, emergency personnel had rescued or evacuated 237 people, including 167 by helicopter, according to Major General Thomas Suelzer, the adjutant general for the state of Texas. More than 20 girls unaccounted for Emergency services are continuing a frantic search to find those missing - including 23 girls.

The children were among more than 700 who were at a summer camp when floodwaters swept through at around 4am local time. Elinor Lester, 13, said she and her cabin mates were woken up by a raging storm at 1.30am and had to be helicoptered to safety.

"The camp was completely destroyed," Elinor said, describing the situation as "really scary". Most of the campers are safe but they could not be immediately evacuated because high waters have made local roads unusable, authorities said.

"Everybody is doing everything in their power to get these kids out," Judge Kelly said. "They could be in a tree.

They could be out of communication," Lieutenant Gov. Dan Patrick said.

"We're praying for all of those missing to be found alive. We're doing everything we can to get in there." Asked why more precautions were not taken amid forecasts for stormy weather, Judge Kelly insisted a disaster of such magnitude was unforeseen.

"We have floods all the time. This is the most dangerous river valley in the United States," he said, adding, "We had no reason to believe this was going to be anything like what's happened here.

None whatsoever." Later, US President Donald Trump told reporters on Air Force One that the floods were "terrible," adding: "We're working with the governor [Greg Abbott]." Search teams are flying 14 helicopters and a dozen drones over the area, while hundreds of emergency personnel are on the ground conducting rescues. People desperately searching for their loved ones have posted comments on a Facebook post from the Kerr County sheriff's office.

One woman said she couldn't reach her daughter, who had rented a cabin with her husband and two children. She pleaded for officials to release the names of those who have been evacuated.

A man in Kerrville told WOAI that his brother's house is missing after the flood, along with the brother, his wife and their two children. Officials said the death toll could change, as rescue operations for an unspecified total number of missing people are still ongoing, and authorities were still working to identify the dead.

It was not clear whether anyone unaccounted for might have ended up among the deceased victims tallied countywide by the sheriff..