Rescuers were on Saturday searching for more than 20 girls missing from a riverside summer camp in the US state of Texas, after torrential rains caused devastating flooding that killed 24 people -- with more rain on the way.

"At this point we're at about 24 fatalities," Kerr County Sheriff Larry Leitha told an evening press conference on Friday, as rescue teams scrambled to locate stranded residents in the south-central Texas region.

Some of the dead were children, Texas Lieutenant Governor Dan Patrick said at a previous news conference.

On Saturday, the National Weather Service warned of more extremely heavy rain and "locally catastrophic" flash flooding to come in the region, located northwest of San Antonio.

"Flash flooding is already occurring," the NWS said in an alert, calling on residents to move to higher ground, and to "act quickly to protect your life."

In Kerrville on Saturday, the usually calm Guadalupe River was flowing fast, its murky waters filled with debris.

"It rained in a day what it usually rains in a year," said local resident Gerardo Martinez, 61.

"The water reached the top of the trees. About ten meters or so," he........

© International Business Times