A quarter of the city of Derna in Libya was destroyed by catastrophic flooding, killing an estimated 15,000 people.
The collapse of a major dam caused devastating damage as a tsunami-like torrent dumped huge amounts of water, mud and debris on residents.
According to local media, over 5,000 people have died so far, but 10,000 more are missing after “entire neighborhoods” were washed into the sea.
Storm Daniel raged across the city of around 125,000 residents on Sunday, inundating citizens with a frightening wall of water.
Libyan reporter Johr Ali told BBC survivors they were living in scenes of “doomsday” devastation.
Government Minister Hichem Abu Chkiouat said after his visit to Derna: “There are bodies everywhere – in the sea, in the valleys, under the buildings.”
“I am not exaggerating when I say that 25% of the city has disappeared. Many, many buildings collapsed.”
Bodies were laid out along streets and hospital corridors as desperate families searched the city for their loved ones.
Mohamad al-Qabisi, director of Wahda Hospital, said 1,700 deaths had already been confirmed in one of the city’s two districts and 500 in the other.
After the devastating earthquake in Morocco, it was the second major disaster to hit North Africa in three days.
Hisham Chkiouat, aviation minister and part of the government’s emergency committee, said earlier BBC that large parts of the city had been washed into the sea.
“I was shocked by what I saw, it’s like a tsunami,” he said.
“A huge quarter has been destroyed – there is a huge number of victims, which is increasing every hour.”
“There are currently 1,500 deaths. More than 2,000 are missing. We don’t have exact numbers, but it is a disaster,” he said, adding that the dam had not been properly maintained for some time.
Libya is in crisis after a decade of civil war and is politically divided between East and West.
Public services have collapsed since a NATO-backed uprising in 2011 that sparked years of unrest.
The internationally recognized government in Tripoli does not control the eastern areas where Derna is located.
The three-member presidential council in Tripoli, which serves as the head of state, asked the international community for help.
Mr. Chkiouat then confirmed that aid was on the way and that the Eastern Administration would accept the help of the Tripoli government.
A plane was dispatched with 14 tons of medical supplies, body bags and more than 80 doctors and paramedics.
Turkey is among countries that have also sent aid, including search and rescue vehicles, rescue boats, generators and food, Reuters said Reports.
After storm Daniel struck Greece last week, it swept across the Mediterranean on Sunday.
The storm flooded streets and destroyed buildings in Derna and hit other settlements along the coast. Benghazi, Libya’s second largest city, was also hit by the storm.
Videos from Derna showed a wide torrent flowing through the city center where a much narrower waterway had previously flowed.
The ruins of collapsed buildings stood on both sides.
Eastern Libya’s Almostkbal television broadcast footage showing desperate civilians stranded on the roofs of their vehicles and calling for help.
“The number of missing people is in the thousands and the death toll exceeds 2,000,” Osama Hamad told al-Masar TV.
“Whole neighborhoods in Derna have disappeared and their residents have been washed away by the water.”
Derna resident Saleh al-Obaidi said he managed to escape with his family despite houses collapsing in a valley near the town.
“People were sleeping and waking up to find their homes surrounded by water,” he told Reuters.
Ahmed Mohamed, another resident, said: “We were sleeping and when we woke up we found water encroaching on the house.”
“We’re inside trying to get out.”
Witnesses said the water level had reached three meters.
Libya’s eastern parliament declared three days of national mourning.
Abdulhamid al-Dbeibah, Prime Minister of the interim government in Tripoli, also declared three days of national mourning in all affected cities and called them “disaster areas”.