UN World Meteorological Organization chief Petteri Taalas said many deaths could have been avoided if early warning and emergency management systems had functioned properly in the war-scarred country.  Photo: AP  

The United Nations is urgently seeking more than $71 million to assist those most in need after deadly flash floods swept Libya over the weekend.

Hurricane-strength Storm Daniel slammed into Libya on September 10, killing 11,300 people, according to the Libyan Red Crescent.

In a flash appeal on Thursday, the United Nations humanitarian agency OCHA said it expects the toll to rise.

The city of Derna, one of the hardest-hit locations, was reduced to a wasteland after two upstream dams burst on Sunday. The entire seaside town of Sousse, meanwhile, remains submerged.

OCHA said estimates suggest 30 percent of the city may have disappeared and with most roads collapsed local authorities are calling for a sea corridor to be established for relief and evacuations.

Calling the situation "catastrophic", OCHA said its humanitarian partners need $71.4 million to respond to the "most urgent needs of 250,000 people targeted out of the 884,000 people estimated to be in need".

On Wednesday, UN OCHA head Martin Griffiths had announced an immediate emergency fund of $10 million.

"Entire neighbourhoods have been wiped off the map. Whole families, taken by surprise, were swept away in the deluge of water," he said in a statement.

"Getting lifesaving supplies to people, prevent a secondary health crisis, and swiftly restore some kind of normality must override any other concern at this difficult time for Libya."

Disaster in Derna

The United States, European Union, Türkiye, United Arab Emirates and several other countries have also already sent or pledged aid, while foreign rescue teams have been deployed to search for survivors and recover bodies.

"Within seconds the water level suddenly rose," recounted one injured survivor who said he was swept away with his mother in the late-night ordeal before they both managed to scramble into an empty building downstream.

"The water was rising with us until we got to the fourth floor, the water was up to the second floor," the unidentified man said from his hospital bed, in testimony published by the Benghazi Medical Center.

"We could hear screams. From the window, I saw cars and bodies being carried away by the water. It lasted an hour or an hour-and-a-half — but for us, it felt like a year."

Hundreds of body bags now line Derna's mud-caked streets, awaiting mass burials, as traumatised and grieving residents search mangled buildings for missing loved ones and bulldozers clear streets of debris and mountains of sand.

"This disaster was violent and brutal," said Yann Fridez, the head of the Libya delegation of the International Committee of the Red Cross, which had a team in Derna when the floodwaters hit.

AFP