A magnitude 6.3 earthquake has shaken northern Afghanistan, killing at least 20 people and injuring more than 500, a health official says, adding that the numbers could increase.

The quake’s epicentre on Monday was located 22km (14 miles) west-southwest of the town of Khulm, and it struck at 12:59am (20:29 GMT on Sunday) at a depth of 28km (17 miles), the United States Geological Survey said.

Sharafat Zaman, a spokesperson for the Ministry of Public Health, said 534 injured people and 20 bodies had been brought to hospitals in Balkh and Samangan provinces. Rescuers were on the scene and the figures were changing, he added.

In the nearby province of Badakhshan, the quake damaged or destroyed 800 houses in one village in the Shahr-e-Bozorg district, said Ihsanullah Kamgar, spokesperson for the provincial police headquarters.

However, due to a lack of internet service in the remote area, there were still no accurate casualty figures, he added.

Yousaf Hammad, a spokesperson for the Afghanistan National Disaster Management Authority, said most of the injured suffered minor wounds and were discharged after treatment.

In the Afghan capital, Kabul, the Ministry of Defence announced that rescue and emergency teams had reached the quake-affected areas in Balkh and Samangan, which suffered the most damage, and were transporting the injured and assisting others.

The Defence Ministry said a rockslide briefly blocked a main mountain highway linking Kabul with Mazar-i-Sharif but the road was later reopened. It said some people who had been injured and trapped along the highway were transported to hospital.