Officials in the Philippines said on Friday that years of disaster-preparedness drills helped prevent a larger casualty toll when one of the strongest earthquakes in 50 years struck the country and left 46 people dead and 38 others missing.

The 7.8 magnitude offshore quake, which struck off Sarangani province on Monday, injured at least 688 people and displaced more than 45,000, about half them still in emergency shelters, after more than 12,600 houses across farming towns and cities were damaged.

The numbers of dead and missing were considerably lowered after multiple verifications, the Office of Civil Defence said in a statement.

Many of the displaced were still too traumatised to return home because of strong aftershocks, officials said.

Days after the earthquake hit, more videos of the chaotic moments have been posted on social media showing horrified crowds witnessing the collapse of small buildings and flag-raising ceremonies turning chaotic when the ground started to shake on the first day of school after a long summer break.