Torrential rains before dawn on Friday deluged the Guadalupe River, which burst its banks and killed dozens of people, leaving behind mangled piles of debris, trees and cars.

Search efforts continue for a fourth day as a girls' summer camp confirms 27 children and staff are dead, with five campers and one counsellor unaccounted for.

Flash floods that swept through Texas over the Fourth of July weekend have left more than 100 people dead and dozens of others missing.