A week after a tsunami-sized flash flood devastated the Libyan coastal city of Derna, sweeping thousands to their deaths, international aid efforts gathered pace as search-and-rescue efforts continued.

Traumatised residents, 30,000 of whom are now homeless in Derna alone, badly need clean water, food, shelter and basic supplies amid a growing risk of cholera, diarrhoea, dehydration and malnutrition, United Nations agencies have warned.

“Thank God for giving us patience. I am sitting here trying to clean and verify who is missing. I am trying to understand the situation. I did not leave,” Hamad Awad, a Derna resident, told Al Jazeera.

“In this city, every single family has been affected,” one resident, Mohammad al-Dawali, told the AFP news agency.

The health minister of the eastern administration, Othman Abdeljalil, has said 3,252 people were confirmed dead in Derna.

The UN’s Office for the Coordination of Humanitarian Affairs (OCHA) has said approximately 11,300 people had died.

The Libyan Red Crescent, which OCHA cited for the data, distanced itself from the report.

Libyan officials and humanitarian organisations warned that the final toll could be much higher, with thousands still missing.

The massive flood came as Libya was lashed on September 10 by the hurricane-strength Storm Daniel, which had earlier brought deadly floods to Greece, Turkey and Bulgaria.

The rapidly rising waters burst two upstream river dams in Derna, sending a late-night tidal wave crashing through the centre of the city of 100,000, sweeping entire residential blocks into the Mediterranean.

According to Badr Al-Din Al-Toumi, head of the government emergency and rapid response, “the team assigned by the government to inventory the damages stated that the total number of buildings in the city is about 6,142 buildings, of which the total number of damaged buildings is 1,500 buildings.

“Out of the 1,500 buildings, 891 buildings have been completely destroyed, 211 buildings have been partially destroyed, and about 398 buildings were submerged in mud.”

Evacuation plans, aid

As local authorities have worked to carry out a complete or partial evacuation plan for the city, the presence of two rival governments has made relief efforts chaotic and accurate information hard to come by.

Damaged roads have made it difficult for aid to enter the city and efforts have been further hampered by the political division of Libya, which plunged into years of war and chaos after a 2011 NATO-backed uprising led to the overthrow and killing of longtime ruler Muammar Gaddafi.

The oil-rich North African country remains split between two rival governments – a UN-backed administration in the capital Tripoli, and one based in the disaster-hit east.

The International Organization for Migration’s Libya chief Tauhid Pasha posted on X, formerly known as Twitter, that the aim now was to channel all authorities “to work together, in coordination”.

The UN has launched an aid appeal for more than $71m. The aid being sent to Libya includes water, food, tents, blankets, hygiene kits, medicines and emergency surgical supplies as well as heavy machinery to help clear the debris, and more body bags.

Emergency response teams and aid have been deployed from France, Iran, Russia, Saudi Arabia, Tunisia, Turkey and the United Arab Emirates, with more on the way from other nations, but international officials say much more help is needed. A French field hospital was being prepared in footage aired by Libya’s Al Masar television.

“People came with aid from all over, and this made it easier on us, and we felt that we are not alone,” said Derna resident Hassan Awad as civil protection workers from Algeria searched the rubble of multistorey buildings in the city for survivors.

Awad pointed to a rusty pole between two buildings and said clinging to it was how his family had survived the flood which tore through their home, covering everything in mud.”

We found dead bodies, of neighbours, friends and loved ones,” he said. On the seafront, an excavator moved smashed furniture and cars to try to find victims underneath. Another excavator cleared rubble from buildings as rescue workers paused and knelt nearby to pray.

In al Badya, a coastal settlement west of Derna, the hospital was treating victims from Derna as well as its own. Doctors built makeshift dams in the street when the flooding hit to try to hold back the water, but it rose within the building.

“This affected machinery and the infrastructure of the lower level of the hospital,” the hospital’s head, Abdel Rahim Mazek, said.

Elsewhere in the town, volunteers handed out clothing and food.

“People left their houses with nothing, they didn’t even have their underwear,” said one of the initiative’s supervisors, Mohammad Shaheen.

Volunteer Abdulnabi said the team came from Ajaylat, around 800 miles (1,200 km) away in western Libya.

“People are coming together to help those impacted,” he said.

UN experts have blamed the high death toll on climatic factors such as the Mediterranean region sweltering under an unusually hot summer and on the legacy of Libya’s war, which has depleted its infrastructure, early warning systems and emergency response.

Questions are being asked about whether the disaster could not have been prevented, as cracks in the dams were first reported in 1998.