MOSCOW (Sputnik) — The tectonic quake struck at 06:13 GMT in Celebes Sea some 140 miles south of Bonguingui municipality in the province of Sulu at a depth of 390 miles, the institute said.
Tremors of slight intensity were reported in the country's southernmost General Santos City, PHIVOLCS said. Aftershocks, but no damage, are expected following the earthquake, it added.
No tsunami threat has been issued in the wake of the tremors, according to an advisory statement by the institute.
The Philippines archipelago nation is located in the so-called Ring of Fire quake zone where a large number of earthquakes and volcanic eruptions occur. The Philippine Trench, located in the Pacific to the east of the islands, is a submarine trench with subducting tectonic activity.