At least four people were killed and more than 200 others injured, when the powerful earthquake struck early on Monday, damaging buildings and prompting tsunami warnings across parts of the region, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).
President Ferdinand Marcos Jr urged people to immediately go to higher ground in Philippine areas vulnerable to a tsunami, and Indonesian and Malaysian authorities also issued warnings to their nearby coastal areas.
The strongest quake to strike the Philippines this year was centred at sea about 13km southwest of General Santos, a city of more than 700,000 people that is a hub for tuna processing and other commerce in the southern Mindanao region of the archipelago nation.
The Philippine leader said disaster-response agencies were on standby to respond.
"The national government is moving and we will not leave Mindanao behind," Marcos said.
Numerous aftershocks followed the 7:37am quake, which was felt in nearby Malaysia. Tsunami waves were also detected in Indonesia and Malaysia.
At least three people were killed and 130 others were injured in General Santos, where at least a few small buildings partially collapsed and several structures, including a key access bridge, sustained dangerous cracks, Rod Sosmeña, regional director of the Office of Civil Defense, told The Associated Press.
The Department of Health said another person died in Davao Oriental province due to the quake.
Sosmeña was being driven to work when the ground violently shook.
"Our pickup truck suddenly jerked and I thought we had a flat tyre," he told the AP by telephone.
"People dashed out of houses into the streets."
The international airport in General Santos was temporarily shut due to the earthquake and 17 domestic flights were cancelled.
Ednar Dayanghirang, director of the Office of Civil Defense in a nearby southern region, said more than 100 students attending flag-raising ceremonies sustained bruises and some fainted in panic at different grade and high schools.
"I myself could hardly stand and keep my balance when the ground shook as I was leaving my house," Dayanghirang told the AP by telephone.
DZRH radio station in Manila reported that a small commercial building housing its provincial branch partly collapsed and staffers dashed to the ground floor.
It wasn't clear if other people were trapped in the rubble of the four-story office building. Debris also fell from other buildings, hitting tricycle taxis parked below.
The quake was caused by movement in the Cotabato Trench at a depth of 10km, according to the Philippine Institute of Volcanology and Seismology.
"It's a major earthquake and we're expecting damages and we've already some damaged buildings based on videos we've seen," institute director Teresito Bacolcol told AP.
One metre waves were monitored in the Philippine provinces of Sultan Kudarat and Sarangani by land-based tsunami watch stations, Bacolcol said. Smaller waves were monitored in at least one other province.
"Please heed the tsunami warning. Move to higher ground now. Do not wait. Your life is more important than anything left behind," Marcos told people in quake-hit provinces.
The Pacific Tsunami Warning Center said tsunami waves up to three metres were possible on some coasts of the Philippines. Waves up to one metre were possible on some coasts of Indonesia and Malaysia.
Malaysia's Meteorological Department issued a tsunami warning for Sabah state on Borneo island. Sabah is just a boat ride away from southern Philippines. An 83cm tsunami was measured by a gauge off Indonesia's Sulawesi island.
Smaller sea changes were possible in Japan, Papua New Guinea and several island nations and territories in the western Pacific. An advisory for Guam was lifted about two hours after the quake and there was no threat to Hawaii, the PTWC said.
Aftershocks up to 6.5 magnitude were measured by the US Geological Survey.
The Philippines is often hit by earthquakes and volcanic eruptions due to its location on the Pacific "Ring of Fire," an arc of seismic faults around the ocean.
with dpa
