The death toll from a 6.9-magnitude earthquake that hit the central Philippines rose to 69 on Wednesday, a disaster official said, as authorities mounted a rescue effort to find survivors after one of the country's strongest quakes in a decade.

The shallow quake struck late on Tuesday off the island of Cebu, cutting power and damaging buildings.

The death toll was 69 as of Wednesday late morning, said Jane Abapo of the regional Civil Defence office, citing data from the provincial disaster agency that was subject to validation.

The national disaster agency earlier said the toll could be as high as 60, with 150 reported injured.

The hospital in Bogo City near the epicentre of the quake was "overwhelmed", Civil Defence official Raffy Alejandro said.

The Philippine coast guard deployed a vessel carrying dozens of doctors, nurses and other medical personnel bound for Bogo, while President Ferdinand Marcos Jr assured survivors of swift assistance, with cabinet secretaries on the ground directing relief operations.

"We are assessing the damage, we are assessing the needs," Marcos said after distributing aid in Masbate, an island recovering from the impact of Super typhoon Ragasa last week.

Mariano Martinez, the mayor of San Remigio municipality close to Bogo, said there were 11 casualties in the area, with victims as young as 12 and the death toll expected to climb.

"Our first main problem is finding the casualties, identifying people who needs help", he told DZMM radio, adding many homes had suffered damage.

Earthquake monitoring agencies put the quake's depth at around 10 kilometres and recorded multiple aftershocks, the strongest having a magnitude of 6. There was no tsunami threat following the quake.

San Remigio vice mayor Alfie Reynes said among those killed were people who were playing basketball in a sports complex when it partially collapsed and appealed for food and water for evacuees, as well as heavy equipment to aid search and rescue workers.

"It is raining heavily and there is no electricity so we really need help, especially in the northern part because there's a scarcity of water after supply lines were damaged by the earthquake," Reynes said.

The Mactan-Cebu International Airport, the country's second busiest gateway, remained operational.

Philippine seismology agency Phivolcs said close to 800 aftershocks have been recorded and warned affected areas to expect more tremors in the coming days, although their strength is expected to gradually diminish.

It reported tremors as far south as Zamboanga del Norte, 330km away. (Reuters)