Over 100 people have died after heavy rain pounded Kerr County, Texas, early Friday, leading to "catastrophic" flooding, the sheriff said.

Five campers and one counselor from Camp Mystic remain unaccounted for, officials say amid mounting questions over who was responsible for monitoring the weather.

The death toll in Kerr County crept up to 87 on Tuesday as search and rescue efforts continued in flood-ravaged central Texas, according to officials in the county worst hit by the disaster, which has killed more than 100 people.