Rescuers are using helicopters to search for survivors in the ruins of remote villages in eastern Afghanistan after a powerful earthquake killed 800 people and injured 1,800 others.

Many are feared trapped under the rubble of their homes after the magnitude 6.0 earthquake struck on Sunday near the country's border with Pakistan.

Authorities searched by air for the second day on Tuesday as roads blocked with debris and the mountainous terrain in the affected areas made land travel difficult.

The Taliban government has appealed for international help. The United Nations has released emergency funds, while the UK has pledged £1m ($1.3m) in aid.

Sunday's earthquake was one of the strongest to hit Afghanistan in recent years. The country is very prone to earthquakes because it is located on top of a number of fault lines where the Indian and Eurasian tectonic plates meet.

There were 90 helicopter flights on Monday to airlift survivors out of remote villages in Kunar province.

The terrain was so rough in one part of the Mazar valley that one helicopter failed to land after three attempts, one Taliban source said.

Survivors have been brought to a hospital in Jalalabad, which was being overwhelmed with hundreds of patients a day even before the disaster.

Mir Zaman told the BBC that he pulled his dead children out of the rubble by himself.

"It was dark. There was no light. Someone lent me a lamp, and then I used a shovel and pick axe to dig them out. There was no one to help because everyone was affected. So many people died in my village. Some are still buried. Whole families have died," he said.

Two-and-a-half-year-old Maiwand suffered head injuries and blood loss.

"You can see his situation. It's so tragic. The earthquake was deadly. I want the doctors to treat him, to cure him," said the child's uncle, Khawat Gul.

At Jalalabad's Nangrahar Regional Hospital, earthquake survivor Nader Khan broke down as he recalled how he lost two sons and two daughters-in-law to the earthquake.

Khan, who is in his 60s, said he was able to save to grandchildren but now he does not know where they are.

"I injured my head and spine, so I couldn't move to save them... I don't know what has happened to the bodies of my sons," he told the BBC.

The most recent earthquake hit Afghanistan when it is reeling under severe drought and what the UN calls an unprecedented crisis of hunger.

The country has also experienced massive aid cuts especially from the US this year which is further reducing the aid that many of these people could have got. This disaster couldn't have come at a worse time.

Britain's Foreign Secretary David Lammy said aid from the UK will be "channelled through experienced partners", the UN Population Fund (UNFPA) and the International Red Cross.

India delivered 1,000 tents to Kabul, its foreign minister Subrahmanyam Jaishankar wrote on X after speaking to his Taliban counterpart Amir Khan Muttaqi.

The Indian mission is also helping to move 15 tonnes of food from Kabul to Kunar province, which has been badly hit by the earthquake, he said, adding that India would send more relief items.

China and Switzerland have also pledged support.

Survivors will need housing, shelter and blankets, said Amy Martin, who leads the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) in Afghanistan.