Libya's eastern port city Derna was home to some 100,000 people before Mediterranian storm Daniel unleashed torrents of floodwater over the weekend. But as residents and emergency workers continued sifting Wednesday through mangled debris to collect the bodies of victims of the catastrophic flooding, officials put the death toll in Derna alone at more than 5,100.

The International Organization for Migration said Wednesday that at least 30,000 individuals had been displaced from homes in Derna due to flood damage.

But the devastation stretched across a wide swath of northern Libya, and the Red Cross said Tuesday that some 10,000 people were still listed as missing in the affected region.

The IOM said another 6,085 people were displaced in other storm-hit areas, including the city of Benghazi.

Harrowing videos spread across social media showing bodies carpeting some parts of Derna as buildings lay in ruins.

"The death toll is huge and around 10,000 are reported missing," Tamer Ramadan, head of the International Federation of Red Cross and Red Crescent Societies delegation in Libya said Tuesday.

More than 2,000 bodies had been collected as of Wednesday morning. More than half of them were quickly buried in mass graves in Derna, according to Othman Abduljaleel, the health minister for the government that runs eastern Libya, the Associated Press reported.

But Libya effectively has two governments – one in the east and one in the west – each backed by various well-armed factions and militias. The North African nation has writhed through violence and chaos amid a civil war since 2014, and that fragmentation could prove a major hurdle to getting vital international aid to the people who need it most in the wake of the natural disaster.

Coordinating the distribution of aid between the separate administrations — and ensuring it can be done safely in a region full of heavily armed militias and in the absence of a central government — will be a massive challenge.

The strife that has followed in the wake of ousted dictator Muammar Qaddafi's 2011 killing had already left Libya's crumbling infrastructure severely vulnerable. So when the storm swelled water levels and caused two dams to burst in Derna over the weekend, it swept "entire neighborhoods… into the sea," according to the World Meteorological Organization.

In addition to hampering relief efforts and leaving the infrastructure vulnerable, the political vacuum has also made it very difficult to get accurate casualty figures.

The floods destroyed electricity and communications infrastructure as well as key roads into Derna. Of seven roads leading to the city, only two were left intact as torrential rains caused continuing flash floods across the region.

Margaret Harris, spokesperson for the U.N.'s World Health Organization said Tuesday that the flooding was of "epic proportions" and estimated that the torrential rains had affected as many as 1.8 million people, wiping out some hospitals.

The International Rescue Committee has called the natural disaster "an unprecedented humanitarian crisis," alluding to the storm damage that had created obstacles to rescue work.

In Derna alone, "challenges are immense, with phone lines down and heavy destruction hampering rescue efforts," Ciaran Donelly, the organization's senior vice president for crisis response, said in a statement emailed to CBS News.

In:
• Red Cross
• Africa
• Civil War
• United Nations
• Libya
• Flooding
• Flash Flooding