The shallow quake struck about 100 kilometres (62 miles) south of Manila at 8:24 am (0024 GMT) and sent students and office workers fleeing from their buildings.
"So far everything's okay. No casualties although this is the epicentre," said Rafael Cuevas, a disaster agency official in Calaca city in Batangas province.
"We felt a strong shake... for less than 10 seconds."
Mabini municipality disaster chief Arnold Panopio said: "At first it was just a slight jolt then it became strong then stopped immediately."
Panopio said no casualties or damage had been reported, but a local high school with around 2,000 students had suspended classes as a precaution.
In Manila, students wearing hard hats and office workers assembled outside buildings, waiting for the all clear to go back inside.
Quakes are a daily occurrence in the Philippines, which sits along the Pacific "Ring of Fire", an arc of intense seismic as well as volcanic activity that stretches from Japan through Southeast Asia and across the Pacific basin.
