The quake occurred 43 kilometers (26.7 miles) from San Antonio at the depth of 85 kilometers (52.8 miles) under the South China Sea, according to the Philippine Institute of Volcanology and Seismology.
There has been no tsunami warning or casualties reported, following the earthquake.
Magnitude 3 or lower earthquakes are weak or almost imperceptible, while magnitude 7 earthquakes and over potentially cause serious damage over larger areas, depending on their depth.
In October 2013, a 7.2-magnitude earthquake hit the central part of the Philippines, killing 220 people and injuring thousands. Over 13,200 houses were destroyed.