The quake struck about 20 kilometres (12 miles away) from Manay in the Mindanao region at 9:43 am (0143 GMT), the United States Geological Survey (USGS) said.

"Destructive tsunami is expected with life-threatening wave heights" on the archipelago nation's east coast, the Philippine Institute of Volcanology and Seismology reported.

Coastal residents in these areas "are strongly advised to immediately evacuate to higher grounds or move farther inland," it added.

There were no immediate reports of damage or casualties.

It struck just 11 days after a 6.9-magnitude quake killed 74 people and destroyed or damaged about 72,000 houses in the central island of Cebu.