UPDATED - A tectonic earthquake with a magnitude of 6.1 (initially reported by the Philippine National Seismic Network at 5.7) hit near Castillejos, Zambales at 5: 11 p.m., Monday, April 22, and was felt in Metro Manila.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said damage and aftershocks were expected.

The quake was strong enough to send people out of their buildings in Quezon City and Pasig City, Metro Manila.