Flash floods in the eastern Libyan city of Derna razed entire neighbourhoods
Flash floods in the eastern Libyan city of Derna razed entire neighbourhoods AFP

Libya's eastern-based administration said on Friday that it would host an international conference next month in the flood-hit port city of Derna to aid reconstruction efforts.

A tsunami-sized flash flood broke through two ageing dams upstream from Derna after a hurricane-strength storm lashed the area on September 10, razing entire neighbourhoods and sweeping thousands of people into the sea.

"The government invites the international community to participate in the conference planned for October 10 in Derna to present modern, rapid projects for the reconstruction of the city," the administration said in a statement.

It said the conference was being held in "response to the demands of residents of the stricken city of Derna and other towns that suffered damage" during the flooding.

Wracked by divisions since a 2011 NATO-backed uprising toppled and killed veteran dictator Moamer Kadhafi, Libya has for years been ruled by two administrations vying for power.

A UN-backed, internationally recognised administration in Tripoli is run by Prime Minister Abdulhamid Dbeibah, while a rival administration in the east is backed by military strongman Khalifa Haftar.

Haftar's forces seized Derna in 2018, then a stronghold of radical Islamists, and with the reputation as a protest stronghold since Kadhafi's days.

The official death toll from the flood stands at more than 3,300 -- but the eventual count is expected to be far higher, with international aid groups giving estimates of up to 10,000 people missing.

The International Organization for Migration on Thursday said more than 43,000 people have been displaced by the flood.

It said a "lack of water supply is reportedly driving many displaced out of Derna" to other areas.

Mobile and internet services were also restored in Derna on Thursday following a two-day disruption that came after demonstrations by angry residents on Monday.

The protests saw hundreds of demonstrators gather outside the city's grand mosque, chanting slogans against the eastern-based parliament and its leader and calling for accountability over the high death toll.

Amnesty International on Thursday reported "arrests of critics and protesters" in Derna, decrying "efforts to choreograph and control media access" to the disaster-hit city.

It also called on the eastern authorities to "immediately lift all undue restrictions... and facilitate the delivery of humanitarian aid to all affected communities".

The dams that burst had developed cracks as far back as the 1990s, Libya's top prosecutor has said, as residents accused authorities of negligence.

Scientists from the World Weather Attribution group said in a report issued on Tuesday that a deluge of the magnitude seen during Storm Daniel in northeastern Libya was an event that occurred once every 300-600 years.

They found the rains were both more likely and heavier because of human-caused global warming, with up to 50 percent more rain during the period.

Map showing buildings and roads destroyed or damaged in the Libyan city of Derna after flooding, according to satellite data from Copernicus, as of September 13
Map showing buildings and roads destroyed or damaged in the Libyan city of Derna after flooding, according to satellite data from Copernicus, as of September 13 AFP
The International Organization for Migration says more than 43,000 people have been displaced by the flood
The International Organization for Migration says more than 43,000 people have been displaced by the flood AFP