Rescuers have found more than 2,000 bodies as of Wednesday in the wreckage of a Libyan city where floodwaters broke dams and washed away neighbourhoods. Officials fear the death toll could exceed 5,000 in the nation made vulnerable by years of turmoil and neglect.

The flooding caused significant infrastructure damage in the coastal city of Derna and displaced at least 30,000 people, the UN migration agency said. The damage is so extensive the city is almost inaccessible for humanitarian aid workers, the International Organisation for Migration said.

Mediterranean storm Daniel caused deadly flooding in many eastern towns, but the worst-hit was Derna. As the storm pounded the coast Sunday night, Derna residents said they heard loud explosions when the dams outside the city collapsed. Floodwaters washed down Wadi Derna, a river running from the mountains through the city and into the sea.

More than 2,000 corpses were collected as of Wednesday morning and over half of them had been buried in mass graves in Derna, said eastern Libya's health minister, Othman Abduljaleel. Rescue teams were working day and night to recover many other bodies scattered in the streets and under the rubble in the city. Some bodies were retrieved from the sea.

The startling devastation pointed to the storm's intensity, but also Libya's vulnerability. The country is divided by rival governments, one in the east, the other in the west, and the result has been neglect of infrastructure in many areas.

The floods damaged or destroyed many access roads to Derna. Of seven roads leading to the city, only two are accessible from its southern edge. Bridges over the river Derna that link the city's eastern and western parts have also collapsed, according to the UN's migration agency. The destruction has hampered the arrival of international rescue teams and humanitarian assistance to tens of thousands of people whose homes were destroyed or damaged.

"The city of Derna was submerged by waves 7 metres high that destroyed everything in their path," Yann Fridez, head of the delegation of the International Committee for The Red Cross in Libya, told France24. "The human toll is enormous." Local emergency responders, including troops, government workers, volunteers and residents, continued digging through rubble looking for the dead. They also used inflatable boats and helicopters to retrieve bodies from the water and inaccessible areas.

"This is a disaster of every sense of the word," a wailing survivor who lost 11 members of his family told a local television station as a group of rescuers tried to calm him. The television station did not identify the survivor.

Ahmed Abdalla, a survivor who joined the search and rescue effort, said they were putting bodies in the yard of a local hospital before taking them for burial in mass graves at the city's sole intact cemetery.

"The situation is indescribable. Entire families dead in this disaster. Some were washed away to the sea," Abdalla said by phone from Derna.

Bulldozers worked over the past two days to fix and clear roads to allow the delivery of humanitarian aid and heavy equipment urgently needed for the search and rescue operations. The city is 250 kilometres east of Benghazi, where international aid started to arrive on Tuesday.

Libya's neighbours, Egypt, Algeria and Tunisia, as well as Turkiye 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.z

Mohammed Abu-Lamousha, a spokesman for the east Libya interior ministry, on Tuesday put the death tally in Derna at more than 5,300, according to the state-run news agency. Dozens of others were reported dead in other towns in eastern Libya, he said.

Authorities have transferred hundreds of bodies to morgues in nearby towns. In the city of Tobruk, is 169 kilometres east of Derna, the Medical Center of Tobruk's morgue received more than 300 bodies for people killed in the Derna flooding; among them were 84 Egyptians, according to a list of dead obtained by The Associated Press.

Dozens of bodies of Egyptians killed in the floods were returned to their home country. A funeral for 22 Egyptians was underway on Wednesday in their village of el-Sharif in the southern province of Beni Suef. Another four were buried in their hometown in the Nile Delta province of Beheira, local media in Egypt reported.

At least 10,000 people were still missing in the city, according to Tamer Ramadan, Libya envoy for the International Federation of Red Cross and Red Crescent Societies. He said 40,000 people have been displaced in Derna and other towns affected by the floods in eastern Libya.

Known for its white-painted houses and palm gardens, Derna is about 900 kilometres east of the capital of Tripoli. It is controlled by the forces of powerful military commander Khalifa Hifter, who is allied with the east Libya government. The rival government in west Libya, based in Tripoli, is allied with other armed groups.

Much of Derna was built by Italy when Libya was under Italian occupation in the first half of the 20th century. The city was once a hub for extremist groups in the years of chaos that followed the NATO-backed uprising that toppled and killed longtime dictator Moammar Gadhafi in 2011.