The 6.8 magnitude quake that hit Morocco late Friday was the strongest in the area in at least 123 years, the United States Geological Survey said.
The earthquake had a depth of about 11 miles, and its epicenter was just over 30 miles west of Oukaimeden, a popular Moroccan ski resort, the U.S.G.S. said in a preliminary report early Saturday.
Oukaimeden is near Toubkal, the highest peak in North Africa, and about 50 miles southeast of Marrakesh, a city of more than 800,000 people. Agadir, a coastal city about 150 miles southwest of Marrakesh by road, has a population of nearly 700,000, according to the U.S.G.S.
The U.S.G.S. said earthquakes this large in the area were “uncommon but not unexpected” and that there had been no earthquakes of 6 magnitude or larger there since 1900.
Many of the vulnerable buildings in the region are made from adobe blocks and unreinforced bricks, it added.