Officials in eastern Libya say more than 5,000 people have died in devastating floods caused by Storm Daniel.
Aid agencies have so far provided lower figures but warn the number of victims could sharply rise as thousands remain unaccounted.
The flooding has wiped out a quarter of the coastal city of Derna, where two dams burst following heavy rains.
The United Nations says emergency teams are being mobilised to help on the ground in the politically divided country.
After more than a decade of turmoil, Libya remains split between two rival administrations: one in the west and the other in the east, each backed by different militias and foreign governments.