A powerful 6.8-magnitude earthquake struck Morocco on Friday night, killing nearly 300 people and forcing many residents to spend the night in the streets in what the United States Geological Survey (USGS) said was the strongest tremor to hit that part of the North African nation in more than a century.

The quake struck in Morocco’s High Atlas mountain range shortly after 11 p.m. local time at the relatively shallow depth of 18.5 kilometers (11.4 miles), USGS said, with the epicenter located about 72 kilometers (44.7 miles) southwest of Marrakech, a city of some 840,000 people and a popular tourist destination.

At least 296 people were killed, and 153 others were wounded, Morocco state-run Al-Aoula television reported on Saturday.

The Royal Moroccan Armed Forces warned that residents were still vulnerable to aftershocks.

“We remind you of the need to exercise caution and take safety measures due to the risk of aftershocks,” the military wrote on X, formerly known as Twitter.

The USGS said Friday night’s quake was unusually strong for the region.

“Earthquakes of this size in the region are uncommon, but not unexpected. Since 1900, there have been no earthquakes M6 (magnitude 6) and larger within 500 km of this earthquake, and only 9 M5 (magnitude 5) and larger earthquakes,” USGS said.

The US body predicted that “significant damage is likely and the disaster is potentially widespread”, noting that many people in the area reside in structures that are “highly vulnerable to earthquake shaking”.