At least 69 people were killed in a powerful earthquake that struck the central Philippine province of Cebu.

The magnitude 6.9 earthquake, which occurred at about 10pm (14:00 GMT) on Tuesday, trapped an unspecified number of residents in collapsed houses, nightclubs, and other businesses in Bogo City and outlying rural towns within Cebu, officials said.

Rescuers scrambled to find survivors on Wednesday. Army troops, police, and civilian volunteers, supported by backhoe diggers and sniffer dogs, were deployed to conduct house-to-house searches for survivors.

The epicentre of the earthquake — triggered by movement along an undersea fault line at a dangerously shallow depth of 5km (3 miles) — was about 19km (12 miles) northeast of Bogo, a coastal city of about 90,000 people in Cebu province, where about half of the deaths were reported, officials said.

The death toll in Bogo was likely to rise, according to officials, who noted that intermittent rain and damaged bridges and roads were hampering efforts to save lives.

“We’re still in the golden hour of our search and rescue,” Office of Civil Defence deputy administrator Bernardo Rafaelito Alejandro IV said during a news briefing. “There are still many reports of people who were pinned or hit by debris.”

Deaths were also reported in the outlying towns of Medellin and San Remigio, where three coastguard personnel, a firefighter, and a child were killed separately by collapsing walls and falling debris while attempting to flee to safety from a basketball game in a sports complex that was disrupted by the quake, town officials said.

The earthquake was one of the most powerful to hit the central region in more than a decade.

Cebu and other provinces were still recovering from Typhoon Bualoi, which battered the central region on Friday, killing at least 27 people — mostly due to drownings and falling trees — knocking out power in entire cities and towns, and forcing the evacuation of tens of thousands.

Schools and government offices were closed in the affected cities and towns while the safety of buildings was assessed. More than 600 aftershocks have been detected since Tuesday night’s earthquake, said Teresito Bacolcol, director of the Philippine Institute of Volcanology and Seismology.

Rain-soaked mountainsides were more susceptible to landslides and mudslides following a major earthquake, he warned.

“This was really traumatic to people. They have been lashed by a storm and then jolted by an earthquake,” Bacolcol said. “I don’t want to experience what they’ve gone through.”

The Philippines, one of the world’s most disaster-prone countries, is frequently affected by earthquakes and volcanic eruptions due to its position on the Pacific “Ring of Fire”, an arc of seismic faults around the ocean. The archipelago is also battered by about 20 typhoons and storms each year.