More than 1,000 people have been killed and at least 1,500 injured. Unknown numbers are buried in the rubble of ruined, often mud-built homes.
South eastern Paktika province has been worst-hit and the UN is scrambling to provide emergency shelter and food aid
Rescue efforts are being hampered by heavy rain and lack of resources.
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.
Afghanistan is in the midst of a humanitarian and economic crisis, and Abdul Qahar Balkhi, a senior Taliban official, said the government was “financially unable to assist the people to the extent that is needed”.
Aid agencies, neighbouring countries and world powers were helping, he said, but added: “The assistance needs to be scaled up to a very large extent because this is a devastating earthquake which hasn’t been experienced in decades.”
The head of the United Nations, António Guterres said the agency had “fully mobilized” over the disaster. Health teams, medical supplies, food, and emergency shelters were en route to the quake zone, UN officials said.