RESCUERS searched ruined buildings in the southern Philippines today, checking that no-one remained trapped the day after one of the strongest earthquakes to hit the country in half a century killed at least 37 people and displaced more than 30,000.

Only four people were officially recorded as missing in the southern provinces near where the 7.8 magnitude quake struck on Monday morning, but the Office of Civil Defence acknowledged that several collapsed and heavily damaged buildings must be thoroughly inspected for possible survivors or casualties.

The earthquake centred off Mindanao, the second most populous Philippine island, injured nearly 500 people and displaced around 32,000, most of whom fled to emergency shelters.

The earthquake left a trail of destruction, including in General Santos, a coastal city of more than 700,000 people, where at least 13 people were killed.

At least 18 died in Sarangani province, mostly in a landslide that buried houses in the mountainside town of Glan, according to Rafaelito Alejandro of the Office of Civil Defence.

The other deaths were reported in the southern provinces of South Cotabato and Davao Occidental and on Balut Island, disaster-response officials said.

President Ferdinand Marcos Jnr has deployed teams from Manila to support search and rescue efforts.