At least 82 people have died, including 27 campers from Camp Mystic, following Texas flash floods that caused devastation over the holiday weekend.

Rescue operations are ongoing in Central Texas after flash flooding along the Guadalupe River left 23 girls from Camp Mystic unaccounted for. Officials say dozens have died as catastrophic floods continue to ravage the Hill Country.

Search efforts continue for a fourth day as a girls' summer camp confirms 27 children and staff are dead, with 10 campers and one counsellor unaccounted for.