The Philippine Institute of Volcanology and Seismology (Phivolcs) said the inland tremor, which struck at 9.04 a.m. local time hit at a depth of 7 km, about 25 km southeast of Tulunan town, reports Xinhua news agency.
It was the second powerful earthquake that rocked the province in the central Mindanao region this month. Tulunan town was also the epicenter of the 6.3-magnitude earthquake that jolted the region on October 16.
The tremor, which was tectonic in origin, so far triggered dozens of large and small aftershocks, ranging from magnitude of 1.5 to 6.1, the institute said.
More than an hour after the initial quake, the institute recorded a 6.1-magnitude aftershock.
The powerful earthquake was strongly felt in the cities of Kidapawan, Davao, Koronadal, Cagayan de Oro, General Santos, Zamboanga and also the Sarangani and Bukidnon provinces.
Local officials said the strong earthquake sent panicking people out of their houses and buildings.
The officials said the tremor cut the power supply in many of the affected provinces, knocked down electric posts and shattered glass.
Patients of a hospital in Kidapawan were evacuated out of the building for safety, they added.
The tremor forced local government units to suspend classes and work in the region.
The Philippines, which lies along the Pacific Ring of Fire, is surrounded with numerous active faults and trenches on both sides of the archipelago.
The country has frequent seismic activity, registering quakes everyday, though most are not felt.
Phivolcs records an average of 20 earthquakes a day and 100 to 150 earthquakes are felt per year.
( With inputs from IANS )