Renato Solidum of Phivolcs said in a televised phone interview that the epicentre of the quake was in Baler town, Aurora.
The quake of tectonic origin occurred at 10:27a.m. and was strong enough to shake buildings.
Phivolcs predicted no major damage in the affected cities and towns, although aftershocks were expected.
Meanwhile, intensity 4 quake jolted Palayan City and Cabiao, Bongabon and San Jose towns in Nueva Ecija, as well as Santiago City in Isabela, Phivolcs said.
The quake was also felt in Metro Manila, with Mandaluyong, Taguig and Quezon Cities under Intensity 3, along with Tarlac City, Cabanatuan, Infanta, Quezon, and Cauayan City in Isabela.
On the other hand, Intensity 2 was felt in the cities of Makati and Manila, and Malolos, Bulacan; San Clemente, Tarlac; Aglipay and Maddela towns in Quirino. Intensity 1 was recorded in Clark, Pampanga.
Magnitude is a measure of the energy released at the source of an earthquake. Intensity gauges the strength of tremors in specific places, and is determined based on its effects on people, human
structures and the environment. With a report from DJ Yap, Philippine Daily Inquirer