HOUSTON, July 4 (Xinhua) -- At least 13 people were killed and more than 20 children from summer camps along the Guadalupe River went missing during the major flash flooding caused by heavy rain overnight in central Texas, the second largest U.S. state, authorities updated Friday afternoon.

There are currently "about 23" kids unaccounted for at Camp Mystic, a private Christian summer camp for girls, Texas Lieutenant Governor Dan Patrick told a news conference Friday afternoon. The camp hosts about 750 children.

Kerr County Sheriff Larry Leitha told a news conference that at least 13 people died in the county due to the severe flooding and several people remain unaccounted for.

Leitha said he expects more fatalities to be reported in the county. ■