Three strong earthquakes rocked a coastal region near the Philippine capital within half an hour of each other Saturday, sending people running out of buildings.
There were no immediate reports of damage or casualties from the quakes, the strongest of which hit the coast close to the town of Mabini, south of Manila.
The first 5.7 magnitude temblor struck inland at 3:08 pm (0708 GMT) followed by the 5.9 quake just a minute later -- their epicentres within a few kilometres of each other, according to US geologists.
The 5.0 quake hit in the same region after another 20 minutes.
AFP reporters saw people running out of office buildings in Manila's financial district, while local television network ABS-CBN broadcast live footage of frightened commuters fleeing the passenger terminal at the port of Batangas, near the epicentres.
ABS-CBN quoted local officials as saying the quakes broke the windows of some houses in the region, but there were no reports of casualties.