Residents of the southern cities of General Santos and Davao said they noticed a mild shaking but there were no signs of damage or panic.
The Philippine Institute of Volcanology and Seismology said the quake, which hit at 1223 GMT, was tectonic in origin with an epicenter off the coast, about 157 kilometers (98 miles) west of the town of Isulan on the southern island of Mindanao.
Earlier, the Hong Kong Observatory said the quake measured 7.1 on the Richter scale.
No aftershocks were expected from the quake and there was no sign of any possible tsunami, the civil defense office said.
Although about five quakes hit the Philippines every day, few if any are felt and only three major, destructive tremors have been recorded in more than 30 years, the volcanology institute has said.
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