MANILA, Jan. 23 (Xinhua) -- An earthquake with a preliminary magnitude of 6.1 struck Zamboanga del Norte province in the southern Philippines on Thursday morning, the Philippine Institute of Volcanology and Seismology reported.
The institute said the quake, which occurred at 11:41 a.m. local time, hit at a depth of 32 kilometers, about 2 kilometers southeast of Siocon town.
The institute warned that the tectonic quake would trigger aftershocks and cause damage.
The archipelagic Philippines has frequent seismic activities due to its location along the Pacific "Ring of Fire." ■