MANILA, May 22 (Xinhua) -- An earthquake with a preliminary magnitude of 6.1 jolted Batangas province on the main Philippine island of Luzon on Sunday, the Philippine Institute of Volcanology and Seismology said.
The institute said the quake, which occurred at 5:50 a.m. local time, hit at a depth of 132 km, about 21 km northwest of Calatagan town.
The tremor was also felt in Metro Manila and the provinces of Bulacan and Oriental Mindoro.
There were no immediate reports of damage or casualties.
The institute said the tectonic quake will trigger aftershocks and can cause damage.
The Philippines has frequent seismic activity due to its location along the Pacific "Ring of Fire." ■