Doctors in Afghanistan have told the BBC that many children may have been killed in Wednesday’s earthquake.
More than 1,000 people died in the disaster and heavy rain, threadbare resources and rugged terrain are hampering rescue workers.
Unknown numbers were buried in the rubble of ruined, often mud-built homes by the magnitude 6.1 earthquake.
The Taliban authorities have called for more international aid. Communication networks are also badly hit.
“We can’t reach the area – networks are too weak,” a Taliban spokesman was quoted by Reuters as saying.
The United Nations is among those scrambling to provide emergency shelter and food aid to remote areas in the worst-hit Paktika province.
Afghanistan’s health system was facing near collapse even before the disaster.
Survivors and rescuers have told the BBC of villages completely destroyed near the epicentre of the quake, of ruined roads and mobile phone towers – and of their fears that the death toll will rise further. Some 1,500 people were also injured, officials say.
Most of the casualties so far have been in the Gayan and Barmal districts of Paktika. Locals report dozens of villages have collapsed.
One woman in hospital in Paktika’s capital told reporters she had lost 19 family members.
“Seven in one room, five in another, four in another, then three in another, have all been killed in my family,” she said from her hospital bed.
“There was a rumbling and my bed began to shake,” another survivor, Shabir, told the BBC.