The death toll from devastating floods in the Texas Hill Country rose to 24 Friday night, officials said, as a the search for more than 20 people missing from a girls summer camp continued through the night.

The US National Weather Service declared a flash flood emergency for parts of Kerr County, located about 105km northwest of San Antonio.

The death toll from flash floods in south-central Texas rose to 24 on Friday, officials said, as the search for at least 20 girls missing from a summer camp continued.