Manila (Agencies): An earthquake of 6.9-magnitude struck off the southern Philippine island of Mindanao on Saturday but there were no immediate reports of casualties or damage, the US Geological Survey (USGS) said.
The quake struck 193km east of the city of General Santos, the USGS said, with a depth of 59km. USGS had earlier reported the quake measured 7.2 in magnitude before downgrading it.
The Pacific Tsunami Warning Center said a tsunami threat existed for parts of the Pacific "closer to the earthquake" but there was no tsunami threat to the US state of Hawaii.
The centre said that tsunami waves are possible within 300km of the quake, in Philippines and Indonesia.
"Hazardous tsunami waves from this earthquake are possible within 300km of the epicentre along the coasts of Indonesia and the Philippines," the Pacific Tsunami Warning Center said.
However tsunami waves were forecast to be less than 30cm high, it added.
The Philippines' government seismology office said cities in the south of the country felt "moderately strong" shaking.
The provincial civil defence office said it had no immediate reports of damage or casualties from the quake.
According to the USGS, there was a low likelihood of casualties and damage, although it warned recent earthquakes in the area had caused landslides.
The Philippines and Indonesia lie on the so-called Ring of Fire, a vast Pacific Ocean region where many earthquakes and volcanic eruptions occur.
The most recent major quake disaster to strike the Philippines was in 2013 when a 7.1-magnitude quake left more than 220 people dead and destroyed historic churches in the central islands.
Indonesia has been hit by two major tsunamis this year. More than 400 people were killed last weekend after an erupting volcano triggered a deadly wave that struck the coastlines of western Java island and south Sumatra.
A quake-tsunami in September killed around 2,200 people in Palu on Sulawesi island, with thousands more missing and presumed dead.