There were no immediate reports of damage.
Phivolcs said the first tremor occurred at 10:30 p.m. Friday with its epicenter traced offshore between the islands of Mindoro and Marinduque, or 35 kilometers west of Boac, Marinduque.
The quake was felt at Intensity 5 in Marinduque, Naujan, Mindoro Oriental, Batangas City and Bauan, Batangas; Intensity 4 in Manila, Lipa City, Batangas and San Pablo City, Laguna; Intensity 3 in Makati City, Puerto Galera, Oriental Mindoro, Talisay, Batangas, and Lucban, Quezon; and Intensity 2 in Quezon City, Tagaytay City and Guinayangan, Quezon.
Phivolcs said a movement on the eastern segment of the Lubang Fault could have caused the quake.
Dr. Renato Solidum, Phivolcs director, said the quake was followed by four aftershocks yesterday at 1:27 a.m. with a magnitude of 3.7, 6:09 a.m., 4.7; 10:53 a.m., 4.6; and 11:45 a.m., 3.8.
The aftershocks were felt in the cities of Quezon, Manila, Lipa, San Pablo and Batangas, Puerto Galera, and Tanauan and Talisay, both in Batangas.
"After an earthquake, it is normal to have aftershocks. In this case, four aftershocks were reported to us," he said.
At least 20 quakes hit the Philippines daily, but most of them are not felt.
Solidum said there was no need to issue a tsunami warning to coastal areas since the tremors, at such magnitudes, were not capable of generating tsunamis.