(Reuters) -The official tally of storm-related deaths across Texas rose to 131 on Monday as authorities warned of yet another round of heavy rains 10 days after a Hill Country flash flood that transformed the Guadalupe River into a killer torrent.

At least a further 166 remain missing, with officials fearing the death toll could soar. Twenty-seven young girls and staff members were killed at Camp Mystic, an all-girls Christian summer camp situated on the bank of the Guadalupe River.

The death toll has now climbed to at least 132, making it America's deadliest rainfall-driven flash flood since 1976.

New flood warnings have been issued along the Guadalupe River in Texas less than two weeks after flooding killed more than 100 people.