A 6.1-MAGNITUDE earthquake hit parts of Luzon island late Monday afternoon, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported early evening that day.

Official as well as news reports cited the earthquake’s initial strength at 5.7-magnitude, affecting such provinces as Batangas and Zambales as well as Metro Manila.

Phivolcs upgraded the earthquake magnitude in its report from 5.7 to 6.1. A Reuters report, citing the US Geological Survey, said the Luzon earthquake had a 6.3 magnitude.

Phivolcs said it located the quake’s epicenter at 18 kilometers northeast of Castillejos, Zambales with a depth of 12 kilometers below the ground. Intensity V was felt in San Felipe, Zambales, Malolos and Obando, Bulacan, Lipa Batangas, Manila, Abucay Bataan, Valenzuela City Magalang, Pampanga, and in Quezon City.

Intensity IV was reported in Pasig City, Makati City, Caloocan City, Meycauayan and San Jose Del Monte, Bulacan, Floridablanca, Pampanga, Villasis, Pangasinan, Tagaytay City, Baguio City, Marikina City, Las Piñas City.

Intensity III was reported in Dasmariñas, Indang, and Gen. Trias in Cavite, Lucban in Quezon, Muntinlupa City, Cabanatuan City, Palayan City, Gapan City, Santo Domingo and Talavera in Nueva Ecija.

Intensity II was felt in Baler in Aurora. Phivolcs said aftershocks are expected following the earthquake.

At Monday evening’s press conference, Phivolcs Deputy Director Bartolome Bautista said, “Maging vigilant ang lahat, i-secure ‘yung places kung nasaan sila. Alisin ‘yung pwedeng matumba, bumagsak (Everyone should be vigilant. Secure the places they are in. Remove objects that might fall)” he said.

Phivolcs and other agencies also reported milder tremors in Mindanao on Sunday. — Vann Marlo M. Villegas with Reuters