More than 300 people have been killed in mudslides and flooding near Sierra Leone's capital, Freetown.
A hillside in the Regent area collapsed early on Monday following heavy rains, leaving many houses covered in mud.
A BBC reporter at the scene said many people may have been asleep when the mudslide occurred.
The number of casualties is expected to rise. Locals were reportedly trying to recover bodies from the rubble and mud with their bare hands.
The worst-hit area is thought to be the Regent district on the outskirts of Freetown, where dozens of houses were submerged when the hillside collapsed at about 06:00 GMT.
Red Cross spokesman Patrick Massaquoi told AFP news agency that 312 were confirmed dead and warned the toll could rise further.
Another spokesman for the Red Cross, Abubakarr Tarawallie, told the BBC that at least 100 properties had been submerged and that some had collapsed after a section of Sugar Loaf mountain came down.
A Sierra Leonean disaster management official, Candy Rogers, said that "over 2,000 people are homeless" as a result of the mudslide in the Regent area, AFP reports.
Mr Rogers said a huge humanitarian effort will be required to deal with the aftermath of the flooding.
At the scene: Search for loved ones
By Umaru Fofana, BBC Africa
People are wailing uncontrollably; one woman told me she had lost more than 11 members of her family in the disaster, while another man said he had lost his wife, mother-in-law and children.
Hundreds of people are still coming to the area to look for their loved ones. Some of them told me they have not been able to find them.
In fact, there is no sign of the dozens of homes that were built at the foot of Sugar Loaf mountain.
They are covered in mud, with large areas of mire in some parts. It looks strong, but it is flaky. The concern is that if people walk there they risk sinking in the mud.
Images posted on Twitter show people wading through streets, waist-deep in muddy water following the downpour in and around Freetown.
Flooding in Freetown, Sierra Leone pic.twitter.com/2g6zEVdkbC— Francis Reffell (@francisreffell) August 14, 2017
Flooding is not unusual in Sierra Leone, where unsafe housing in makeshift settlements can be swept away by heavy rains.
The rains often hit areas in and around Freetown, an overcrowded coastal city of more than one million people.
In 2015, Freetown endured deadly floods sparked by monsoon rains that killed 10 people and left thousands more homeless.