COTABATO, Philippines, Oct. 8 (Xinhua) -- A magnitude-6.7 quake struck at the ocean near southern Philippines early Thursday, the United States Geological Survey reported.
The quake, 582.8 km below seabed, was recorded at 5:41 a.m. (2141 GMT Wednesday), with the epicenter at 320 km south of Zamboanga in the southern tip of Mindanao region.
No casualties or damages were reported. There was no tsunami alert either.
The Philippines sits on the Pacific "Ring of Fire" where continental plates collide causing frequent seismic and volcanic activity.
The worst earthquake in the country happened on August 16, 1976after a tsunami caused by a quake killed between 5,000 and 8,000 people in the Moro Gulf region in southern Philippines.