MANILA (UPDATE) - A magnitude 6.1 quake struck off the shores of Davao Occidental on Sunday morning, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
It was downgraded from an initial measurement of magnitude 6.5.
The tremor, located southeast of Sarangani Island of the municipality of Sarangani in Davao Occidental at a depth of 156 kilometers, was recorded at 7:48 a.m.
It was tectonic in origin.
Intensity II or a "slightly felt" shaking was reported in Cateel, Davao Oriental, according to Phivolcs.
The Phivolcs said there was no expected damage from the quake but aftershocks were likely to occur.
The Philippines is part of the Pacific Ring of Fire, where frequent volcanic eruptions and earthquakes take place.