The magnitude 7.8 earthquake struck off the island of Mindanao shortly before 7:40 am local time on Monday (23:40 GMT, Sunday), according to the United States Geological Survey. 

The initial earthquake was followed by more than an hour of aftershocks, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).

Philippines Police spokesperson Robert Dagun reported that General Santos, a city of 722,000 people in southern Mindana sustained most serious damage. While the city's St Elizabeth Hospital was severely damaged, forcing patients and medical personnel to evacuate and operate outside the main hospital building temporarily. 

According to the state-run Philippine News Agency, about 3.2 million students and 128,000 teachers and school personnel were affected on what was expected to be the first day of the school year. 

Philippine President Ferdinand Marcos Jr. said emergency agencies, including the Office of Civil Defence and the National Disaster Risk Reduction and Management Council, had been mobilized to coordinate rescue and relief efforts.

“The safety of our children comes first,” Marcos said, announcing the closure of schools in affected areas.

The earthquake also triggered tsunami warnings in several Asian countries. While authorities later lifted warnings in the Philippines and Indonesia, a tsunami advisory remained in place along Japan’s southern coast and outlying islands, where residents were urged to stay away from coastal areas and river mouths.