The Associated Press / Locals search among the rubble of a destroyed house after a 6.3-magnitude powerful earthquake in a rural area of the Khulm District, Samangan Province, northern Afghanistan, on Monday.

KABUL, Afghanistan — A powerful 6.3 magnitude earthquake shook northern Afghanistan before dawn Monday, killing at least 20 people and injuring more than 640 others, as well as damaging the historic Blue Mosque, officials said.

The numbers of people killed or injured could rise, officials said.

In the town of Khulm, near the epicenter, people dug through the rubble of collapsed mud brick homes with shovels and picked through debris to salvage what belongings they could.

Local resident Ahmad Zia said the air was polluted from all the dust that rose from the ruins of houses. “We pulled the bodies of two people from the rubble, and their funerals will be held today,” he said.

Footage on social media from Mazar-e-Sharif, the capital of northern Balkh province, showed several bricks had fallen from the walls of the Blue Mosque but the structure remained intact. The centuries-old site, one of Afghanistan’s most revered religious landmarks, is a major gathering place during Islamic and cultural festivals.

The impoverished country often faces difficulty in responding to such natural disasters, especially in remote regions. Buildings tend to be low-rise constructions, mostly of concrete and brick, with homes in rural and outlying areas made from mud bricks and wood, many poorly built.

In August, a quake in eastern Afghanistan killed more than 2,200 people.

Hundreds of houses destroyed

The U.S. Geological Survey said the quake’s epicenter was located 14 miles west-southwest of the town of Khulm, and that it struck at 12:59 a.m. at a depth of 17 miles.

The deputy spokesman for Afghanistan’s National Disaster Management Authority, Qari Taj Mohammad Hemat, said the earthquake had struck Balkh, Samangan, Sar-e-Pul, and Kunduz provinces and had left 20 people dead and 643 others injured, of whom 25 were in critical condition.