Thunderstorms and torrential rain triggered deadly flash flooding today along the Guadalupe River in south-central Texas, killing at least 13 people and leaving more than 20 girls from a summer camp missing, according to local authorities.

The National Weather Service issued at least five flash flood emergencies, the most severe form of flood warning, Friday in several counties in south-central Texas.

Authorities in the US state confirmed more than 20 children who attended a summer camp were still missing as a result of the flooding along the Guadalupe River.

Officials in Texas say at least 24 people have been killed, and up to 25 children are missing, after heavy rain led to flash flooding in the US state.

Multiple deaths have been reported in Texas after heavy rain caused flash flooding. Click for the latest.

July 4 (UPI) -- At least 13 have died, and more than 20 girl campers are missing amid deadly flooding along the Guadalupe River in Kerr County, Texas, and beyond.

The U.S. National Weather Service issued a flash flood emergency advisory for the Llano River in Mason County, about 120 miles (193 km) north of San Antonio, Texas. In Kerr County, about 90 miles south of Mason County, the Sheriff's Office reported "catastrophic flooding" in the area, resulting in several people missing and "confirmed loss of life."

Flash floods in Texas Hill on July 4 killed 24 and caused mass devastation. Rescue efforts continue amid no warning system and damaged summer camps.

Months worth of heavy rain fell over just a few hours overnight in central Kerr County, Texas, causing flash flooding of the Guadalupe River.