MANILA (2nd UPDATE) - A strong earthquake jolted Zambales at around 10:27 p.m. on Thursday, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).
Phivolcs initially recorded the tremor at magnitude 5.5 before downgrading it to magnitude 5.4.
The epicenter of the quake was located 12 kilometers northeast of the town of San Marcelino.
The quake, which was tectonic in origin, had a depth of 78 kilometers, according to Phivolcs.
The tremor, which was felt in Metro Manila, is expected to trigger aftershocks, Phivolcs said.
It was felt at Intensity IV in Quezon City, Pateros, and Malolos in Bulacan.
The tremor was felt at Intensity III in Tagaytay City; Talisay Batangas; San Jose Del Monte, Bulacan; Pasay City; Makati City; Mandaluyong; Manila City; Paranaque City; Taguig City; San Miguel, Tarlac and Marilao, Bulacan.
Intensity II was reported in Palayan City in Nueva Ecija, Bacoor, Cavite and San Jacinto in Pangasinan.
No damage is expected from the earthquake.