The quake struck early in the morning about 20 km (12.4 miles) off Sarangani province and triggered tsunami warnings across several countries. Tremors were felt strongly across Mindanao and as far as Manado in Indonesia’s Sulawesi island, 420 km (261 miles) away.
Philippine authorities, backed by military and disaster response teams, said they were verifying reports of 32 dead and 134 injured across Mindanao, mostly due to falling debris and landslides.
Tsunami warnings were later cancelled after more than six hours in the southern Philippines, northern Indonesia, and Malaysia’s Sabah state on Borneo, where coastal residents had been ordered to evacuate to higher ground.
The disaster struck eight months after the Philippines’ deadliest quake in 12 years, when a 6.9-magnitude tremor hit Cebu, killing 79 people. Two more strong quakes later struck Mindanao, the strongest measuring 7.4.We will not leave Mindanao behind,' president says
President Ferdinand Marcos Jr ordered an immediate disaster response in Mindanao, an island the size of South Korea, with agencies directed to prepare relief supplies and evacuation centres and be ready for possible rescue operations.
"The national government is moving and we will not leave Mindanao behind," he said in a statement.
It comes eight months after the Philippines suffered its deadliest remor in 12 years, when a shallow 6.9 magnitude quake hit off the island of Cebu, killing 79 people. Two powerful quakes struck Mindanao two weeks later, the strongest at a magnitude 7.4.
The Philippines and Indonesia experience hundreds of quakes each year and sit on tectonically complex parts of the "Pacific Ring of Fire", a seismically active belt stretching from South America to the Russian Far East.
The Philippine seismology agency said at least nine strong aftershocks were felt across Mindanao on Monday morning, the highest at a magnitude 6.7.The full extent of the damage was not yet clear and authorities said assessments were underway.
Video shared by the local government in General Santos, a city of about 700,000 people, showed the collapse of a building housing a fast food restaurant, with panicked onlookers fleeing as a cloud of dust spread quickly through the air.
One General Santos hospital was evacuated due to concerns about cracks on higher floors, while one of the buildings at the city's Notre Dame of Dadiangas University collapsed, but no one was inside.
"I had to duck and shelter myself under the table. And it was very long and strong," the university's president Manuel de Leon told broadcaster DZMM.Images from authorities in Sarangani province showed damaged shop fronts with collapsed signs, smashed windows and piles of rocks from crumbled concrete.
The Philippine military said its disaster response units had been deployed to affected areas.
A video shared by a local school the moment the quake struck showed a large group of children sitting on the floor swaying rapidly from side to side, some hugging teachers, before fleeing en masse as a makeshift shelter collapsed behind them.
Benjie Ancheta, police chief of Sarangani's Alabel town, said the quake occurred during a police flag-raising ceremony, causing some people to faint."This is the strongest earthquake we've experienced," Ancheta said by phone.
Malaysian Prime Minister Anwar Ibrahim said his government was ready to assist the Philippines."I pray for the safety and wellbeing of all those affected, wishing them strength and courage in the difficult days ahead," Anwar posted on X
The US Tsunami Warning System said multiple countries could be affected and Australia initially warned of potential tsunami waves on its northern coasts. Japan's meteorological agency issued an advisory and said a tsunami of 0.2 m or lower had been observed, with some disruption to ferries and precautionary beach closures.
Witnesses in Indonesia's Manado said they felt the quake strongly. Only minor damage was reported, according to Abdul Muhari, spokesperson for Indonesia's disaster mitigation agency.
A tsunami with a wave height up to 0.75 m was detected in some regions in North Sulawesi, where people started moving to safer areas, including residents of the remote Sangihe Islands, among the closest to the Philippines.
"They are now evacuating to the higher ground... away from the coast, to avoid the potential tsunami," resident Jufry Dalita said, according to state news agency Antara.