Most of the damage from the earthquake is believed to be found in Kunar province, nearly 90% of its terrain is mountainous.

Roads leading to the quake-hit areas are very narrow - and many of them have been blocked by landslides triggered by the earthquake.

This complicates rescue efforts. At the moment, the only way to reach survivors is by helicopters.

We saw similar difficulties during the 2022 earthquake, which killed some 1,000 people. Search and rescue efforts in remote villages were hampered by landslides, and had to be carried out by air.

Hafizullah Maroof
BBC Afghan Service

Image source, Supplied

It is just past 06:30 (03:00 BST) in Afghanistan, and several of the wounded - including children - have been taken by helicopters from the quake-hit Mazar valley in Kunar province, according to pictures and footage provided by the government.

They show several injured people being moved from the helicopters to ambulances.

Taliban defence officials involved in the rescue operation told me several villages have been completely destroyed and as many as “hundreds of people” are believed to be killed and wounded - just from this one valley. However, this toll has not been officially confirmed.

It's hard to confirm the death toll immediately, as the affected areas are remote and mountainous. As we've previously reported, the BBC has heard from several sources that entire villages in the region have been buried under rubble.

Hafizullah Maroof
BBC Afghan Service

Several residents in Kunar and Nangarhar provinces told me that they have felt multiple aftershocks last night.

Polad Noori, 28, was standing on a street outside his home in Nangarhar province at midnight, due to the fear of aftershocks.

He said he counted as many as 13 aftershocks and that hundreds of people have fled their homes to the streets.

“I have never seen such a strong earthquake in my life,” he said.

Hafizullah Maroof
BBC Afghan Service

Image source, Supplied

Two sources in Kunar province tell me that at least four helicopters carrying medical staff arrived in Mazar valley in Kunar province early this morning.

This is the most devastated area where roads have been blocked by landslides.

The medical staff will first try to treat wounded, and the critically injured will be airlifted to the capital Kabul or nearby hospitals.

However, given the scale of the devastation, officials say a lot more help would be urgently required.

Afghanistan 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.

In 2022, at least 1,000 people were killed and another 3,000 were injured when a 5.9-magnitude earthquake struck eastern Afghanistan - the deadliest such disaster in the country in two decades.

While that earthquake had been of moderate magnitude, it was so destructive because it was shallow - happening at just 10km (6 miles) under the earth's surface.

The depth of the quake on Sunday was even shallower, at 8km (5 miles). Hundreds are feared dead or wounded.

Afghanistan's residents are also particularly vulnerable to earthquakes because the buildings there, built with timber, mud brick, or weak concrete, tend not to be earthquake resistant.

A lot of damage from earthquakes in Afghanistan's mountains also comes from the landslides they cause, which can flatten houses and block rivers. Landslides also impact roads, which make it difficult for rescue workers and equipment to reach remote locations.

Hafizullah Maroof
BBC Afghan Service

Taliban government officials have urged aid organisations to aid the rescue effort in the remote mountainous areas.

The police chief of Kunar province tells the BBC roads to the area are blocked due to landslides caused by flooding and quake aftershocks.

He said rescue operations can only be carried out by air.

The Taliban officials say they have limited resources and are requesting help from international organisations to provide helicopters to reach affected areas.

The US Geological Survey (USGS), a governmental department which monitors earthquakes, suggests hundreds of people could be killed in this quake.

Modelling on its website estimates that "significant casualties are likely" as the disaster is potentially "widespread".

The USGS notes that previous earthquakes in the region at the same alert level have required a regional or national level response.

So far 20 people have been confirmed to be killed.

Multiple sources from the Taliban government have told the BBC that “dozens of houses are under rubble” and it is now feared that hundreds of people could be killed and wounded in the earthquake. This has not been officially confirmed as yet.

It is believed that mostly houses are damaged in Mazar valley, in the Norgal district of Kunar province which shares a border with Pakistan.

The valley is located in a mountainous area.

So far 20 people have been confirmed killed in the quake.

Hafizullah Maroof
BBC Afghan Service

Dozens of volunteers have rushed to hospitals to donate blood to victims in Nangahar province.

So far nine people have been confirmed dead there.

Taliban government deputy governor Azizullah Mustafa told the BBC that almost 30 people have been taken to hospitals in the district he oversees.

The BBC also spoke to officials in Nangarhar and Kunar who said 115 people were in hospital in both provinces.

Image source, US Geological Survey

Casualties are being reported in Nangarhar and Kunar provinces in eastern Afghanistan, near the Pakistan border.

The earthquake's epicentre was 27km (17 miles) away from Jalalabad, the capital of Nangarhar province and Afghanistan's fifth-largest city.

The quake follows flooding in Nangarhar on Friday and Saturday, which devastated properties and killed five people, according to authorities.

Tremors were felt 140km (87 miles) away in Kabul, as well as more than 200km (124 miles) away in Pakistan's capital Islamabad, AFP reported.

Earthquakes are common in Afghanistan, which sits on major fault lines where the Indian and Eurasian tectonic plates meet.

At least 20 people have died after a 6.0-magnitude earthquake hit eastern Afghanistan, near its border with Pakistan, local officials have confirmed to the BBC.

More than 115 injured people have been taken to hospitals in Nangarhar and Kunar provinces, the officials say.

The shallow quake, with a depth of 8km (5 miles), struck at 23:47 local time (20:17 BST) on Sunday, according to the US Geological Survey. Since then, there have been at least three aftershocks - with magnitudes ranging from 4.5 to 5.2.

The quake shook in Afghanistan's capital Kabul - around 140km away from the epicentre - for several seconds. Tremors were also felt in Pakistan's capital Islamabad, nearly 230km away, AFP reported.

The death toll is expected to climb - the affected provinces are remote and have rugged terrain, and houses there are not generally earthquake-resistant.

We'll continue to bring you the latest updates as we get them. Please stay with us.