At least 350 people have been killed and many more are missing, the UN says, after a landslide hit the north-east Afghan province of Badakhshan.
Hundreds of homes were buried under mud and rocks when a section of a mountain caved in following torrential rain.
Rescuers have reached the area and are searching for survivors.
The BBC’s David Loyn in Kabul says much of north and east Afghanistan has been hit by heavy rain in recent days, and some 150 people have died in flooding.
But our correspondent says this disaster appears to be on a far bigger scale.
“The number of deceased has increased to 350 and significant displacement is expected,” the UN mission in Afghanistan said in a statement.
“The UN Office for the Coordination of Humanitarian Affairs (OCHA) is helping with coordinating local authorities to rescue those still trapped.”
Tons of mud
About 1,000 houses were affected – 300 of them buried immediately after the side of a mountain slipped downwards.
As it was Friday morning, a day off in Afghanistan, people were at home when the landslide happened and whole families were lost under tons of mud.
Hundreds of other houses are also threatened.
Rescue ‘physically impossible’
Badakhshan police commander Fazludeen Ayaz told the BBC that all of the village of Hargu – home to 215 families – was covered by earth and rock.
He said that it was unlikely that anyone would be rescued alive from under the rubble and that even if there was rescue equipment available in the remote area, it would be difficult to dig people out.
The BBC’s Qurbon Ali Hamzi in Badakhshan says that it is still raining and there are fears of further landslides.
Badakhshan is located in the most remote and mountainous part of the country, bordering Tajikistan, China and Pakistan.
Searching for survivors is a huge task, our correspondent reports.
The governor of Badakhshan province Shah Waliullah Adeeb told the AP news agency that rescue crews did not have enough equipment and appealed for shovels.
“It’s physically impossible right now,” Mr Adeeb said. “We don’t have enough shovels; we need more machinery.”
He said that residents of nearby villages had been evacuated amid concerns about further landslides.
Police say that the landslide happened about lunchtime in Afghanistan on Friday.
A smaller landslide was reported in Badakhshan on Thursday.
Source: BBC