MANILA (2nd UPDATE) - A magnitude 4.5 aftershock struck Zambales province early Wednesday, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.

The quake was felt in parts of Luzon, including in Metro Manila, but there was no immediate report of damage.

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State seismologists said the tremor occurred at 2:02 a.m. at a depth of 11 kilometers northeast of Castillejos town.

Intensity 3, which may felt like a passing of a light truck, was recorded in Olongapo City. Quezon City, Muntinlupa City, and Taguig City experienced intensity 2, which may cause hanging objects to swing lightly.

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Meanwhile, instrumental intensity 3 was recorded in San Ildefonso in Bulacan, Olongapo City, and Guagua in Pampanga while instrumental intensity 1 was felt in Talisay in Batangas, Tagaytay City, Palayan City and Gapan City in Nueva Ecija, Quezon City, Pasig City, Malolos City in Bulacan, and Magalang in Pampanga.

Phivolcs earlier measured it as a 4.4 quake that centered on Dinalupihan town in Bataan, but later revised it.

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The tremor occurred while many terrified Filipinos are still reeling from Monday's 6.1-magnitude quake that rocked Luzon, leaving at least 16 people dead and dozens injured.

Almost 600 aftershocks were recorded so far by Phivolcs in the wake of the strong quake. Eight tremors were felt and 62 were "plotted," which means that their epicenters were identified. The magnitudes of the aftershocks ranged from 1.4 to 4.5. - With a report from Lyza Aquino, ABS-CBN News