One of Afghanistan's worst earthquakes killed more than 800 people and injured at least 2,800, authorities said on Monday, as rescuers struggled to reach remote areas due to rough mountainous terrain and inclement weather.

Sharafat Zaman, spokesperson for the health ministry in Kabul, called for international aid to tackle the devastation wrought by the quake of magnitude 6 that struck around midnight local time, at a depth of 10 km (6 miles).

"We need it because here lots of people lost their lives and houses," he told Reuters.

The quake killed 812 people in the eastern provinces of Kunar and Nangarhar, government spokesperson Zabihullah Mujahid said.

Rescuers were battling to reach remote mountainous areas cut off from mobile networks along the Pakistani border, where mudbrick homes dotting the slopes collapsed in the quake.

The quake razed three villages in Kunar, with substantial damage in many others, authorities said. At least 610 people were killed in Kunar with 12 dead in Nangarhar, they added.