New Delhi, June 10 -- Rescuers searched ruined buildings in the southern Philippines on Tuesday to ensure no one was still trapped a day after one of the strongest earthquakes to hit the country in a half-century killed at least 37 people and displaced more than 32,000.

Only four people were considered missing on official records in the southern provinces near where the 7.8 magnitude quake struck Monday morning, but the Office of Civil Defense acknowledged several collapsed and heavily damaged

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

Many people who left their homes feared a tsunami. Waves up to 1....