The death toll from flooding in Libya has risen to more than 3,000, a minister in the administration that controls the east of the country has said, as the extent of the damage to Derna, the port city where two dams burst over the weekend, became more clear.

Entire neighbourhoods have been washed away in Derna. More than 700 bodies have piled up in the cemetery waiting to be identified and local health officials said as as many as 5,000 people were missing.

The health minister for the government in the region, Othman Abdel Jalil, said the death toll had risen to 3,000.

“The number of missing people is in the thousands, and the number of dead is expected to reach 10,000,” Jalil told the Al-Massar TV channel. About 100,000 people were missing, he said.

“The situation in the city of Derna is becoming more tragic, and there are no final statistics on the number of victims,” he added. “Many neighbourhoods were inaccessible.”

Hichem Chkiouat, the minister of civil aviation, said the situation in Derna was “disastrous”.

“Bodies are lying everywhere - in the sea, in the valleys, under the buildings,” Chkiouat told Reuters by phone after a visit to the city. “I am not exaggerating when I say that 25% of the city has disappeared. Many, many buildings have collapsed.”

The final toll would be “really, really big”, he added.

Desperate citizens were appealing on social media for information about missing relatives. Many were angry at the slow pace of the relief effort, and inquests were starting about warnings given previously that the city’s Wadi dams needed reconstruction.

A 2022 report in an academic journal had warned that if a flood equivalent to a flood in 1959 was repeated “it was likely to cause one of the two dams to collapse, making the residents of the valley and the city of Derna vulnerable due to a high risk of flooding”.

Oil-rich Libya has been riven by political infighting, corruption and external interference since a 2011 uprising that toppled and later led to the death of the longtime ruler Muammar Gaddafi. Attempts stretching back a decade to form a unified functioning government have failed, and instead two rival governments backed by their own militias are based in Tripoli in the west and Tobruk in the east.

Investment in the country’s roads and public services has dwindled and there has been minimal regulation of private building.

An emergency medical supply plane carrying 14 tonnes of supplies, medications, equipments, body bags and 87 medical and paramedic personnel was heading to Benghazi to support the areas affected by the flood, the head of the Tripoli-based Government of National Unity, Abdul Hamid Dbeibeh, said on Tuesday.

Gen Khalifa Haftar, the warlord in charge of an army in the east, who is supported by the United Arab Emirates and Egypt, also said aid was arriving.

The flooding caused by Storm Daniel led to a complete break in communications and cut off the internet in Derna. Entire neighbourhoods by the bank of a swollen river had been ravaged and washed away.

Residents were given no immediate warning that the dams were at risk of bursting. Engineers had previously issued generalised warnings about the risk of the dams bursting, and the urgent need to strengthen their defences.

Video footage circulating on social media showed people pleading for help and screaming as muddy water engulfed their homes. Other video captured torrents sweeping away cars on streets, which had turned into rivers.

One resident, Hudhayfah al-Hasadi, told Al Hurrah: “The depths of some of the valleys in which water collects reach about 400 metres. Therefore, when the dam collapsed, the water was released like an atomic bomb, and eight bridges and residential buildings collapsed completely.”

A spokesperson for the Libyan Emergency Authority, Osama Ali, said: “All the water headed to an area near Derna, which is a mountainous coastal area … Houses in the valleys that were on the flood line were swept away by strong currents of muddy water that carried vehicles and debris.”

He added” “Weather conditions were not studied well, sea water levels, rainfall, and wind speed, and there was no evacuation of families who could be in the path of the storm and in the valleys.”

There were conflicting reports as to whether requests had been made to evacuate the city at the weekend, and if so why the plan was rejected.