A strong earthquake of 6.9 magnitude struck off the southern Philippine island of Mindanao on Saturday, raising fears of dangerous tsunami waves across the region but after about two hours, the tsunami warning was withdrawn, Reuters has reported.

There were no reports of casualties or damage from the earthquake, which the U.S. Geological Survey, USGS, said struck 193 km (120 miles) east of the Philippine city of General Santos, at a depth of 60 km (37 miles).

The Pacific Tsunami Warning Centre initially said "hazardous tsunami waves" were possible within 300 km (186 miles) of the epicentre", along the coasts of the Philippines, Indonesia and the Pacific island nation of Palau. But about two hours after the quake struck, the centre said there was no longer a tsunami threat.

The USGS initially said the magnitude of the quake was 7.2 but later downgraded it to 6.9.

Residents of the southern Philippines said the earthquake lasted about a minute and people rushed out of buildings but there had been no major damage, Reuters concluded.