Search teams today continued to comb streets and wrecked buildings for bodies in the coastal city that was at the centre of catastrophic floods sparked by Storm Daniel on Sunday.
Two dams collapsed and unleashed a massive flash flood that swept multi-storey buildings into the sea with sleeping families inside.
Mayor Abdulmenam Al-Ghaithi told al-Arabiya TV he estimated between 18,000 and 20,000 people could have died based on the number of wiped-out districts in the city.
More than 5,000 people have been confirmed dead and at least 9,000 are known to be missing.
At least 30,000 people have been displaced and as much as a quarter of the city, which had a population of around 90,000 has disappeared, emergency officials said.
King Charles reaffirmed the UK’s support for the country in a message sent to the head of Libya’s Presidential Council, Dr Mohamed Menfi, yesterday evening.
It read: “Your Excellency, my wife and I are so desperately saddened by the devastating impact and loss of life caused by Storm Daniel and the subsequent floods.
“We mourn with all those who have lost their loved ones, and continue to pray for everyone whose lives and livelihoods have been affected by the horrific floods.
“I admire greatly all those who are engaged tirelessly in the rescue efforts in such dire conditions, and praise their selfless bravery.
“I know that my Government stands ready to support your needs. Charles R.”
His message comes after the UK Government announced support “worth up to £1 million”.
The Foreign Office said the funding was an “initial package” to provide assistance for those most affected by the devastation.
“Bodies are everywhere, inside houses, in the streets, at sea. Wherever you go, you find dead men, women, and children,” Emad al-Falah, an aid worker from Benghazi, said.
Waves measuring 23ft high “destroyed everything in their path”, Yann Fridez, head of the delegation of the International Committee for The Red Cross in Libya, said. “The human toll is enormous,” he said.
The “sea is constantly dumping dozens of bodies”, Hichem Abu Chkiouat, minister of civil aviation in the administration that runs eastern Libya, said, adding that reconstruction would cost billions of dollars.
Libya’s neighbours, Egypt, Algeria and Tunisia, as well as Turkey and the United Arab Emirates, have sent rescue teams and humanitarian aid.
President Joe Biden also said the United States is sending emergency funds to relief organisations and coordinating with the Libyan authorities and the UN to provide additional support.
But the arrival of aid has been hampered due to the destruction of roads leading to the city.
Bridges over the Derna river that links the city’s eastern and western parts have also collapsed, according to the UN’s migration agency. There was significant damage to roads and telecoms networks.
The country is divided by rival governments on the east and west, and there has been neglect of infrastructure in many areas.