MANILA, July 24 (Xinhua) -- An earthquake with a preliminary magnitude of 6.7 struck Batangas province in the Philippines, south of Manila, before dawn on Saturday, the Philippine Institute of Volcanology and Seismology reported.

The institute said the quake hit at 4:49 a.m. local time, 16 km southwest of Calatagan town. It occurred at a depth of 116 km, the institute said.

The institute said the quake, which was tectonic in origin, can trigger aftershocks but not cause damage.

The Philippines has frequent seismic activity due to its location along the Pacific "Ring of Fire."