Officials in the eastern administration of Libya say at least 3,000 people had been killed by floods resulting from Storm Daniel, which broke through two dams on the Derna river.
Thousands more are missing, with estimates varying from 5,000 to 10,000 people, as a result of a wall of water that swept away entire neighbourhoods.
“The number of bodies recovered in Derna is more than 1,000,” Hichem Chkiouat, minister of civil aviation and member of the emergency committee, told Reuters by phone.
“It is very disastrous. Bodies are lying everywhere,” he said, adding that he expects the final toll to be “really, really big”.
Libya is divided between east and west and public services have crumbled in more than a decade of power struggles.
After pummelling Greece last week, Storm Daniel swept in over the Mediterranean on Sunday, swamping roads and destroying buildings in Derna, and hitting other settlements along the coast, including Libya’s second-biggest city of Benghazi.