6.8 magnitude earthquake hits off Philippines' Mindanao island
The shallow quake hit just before 6:30 a.m. (2230 GMT) about 20 kilometers from the village of Barcelona on the east of Mindanao island, the USGS said.
Many people would have been sleeping when the strong shaking jolted them from their beds.
It did not trigger a tsunami alert, according to the U.S. Tsunami Warning System and the Philippine seismological agency.
The local seismological agency also said no damage was expected from the earthquake, but it warned of aftershocks in the region.
In Lingig municipality, where Barcelona is located, local disaster officer Ian Onsing said he was awakened by the shaking.
"The shaking was quite strong. The things around here were moving. I guess, the shaking took around 10-15 seconds," Onsing told AFP by telephone.
"I'm not expecting any more damages, but we will go around the area again around 8:00 am just to be sure," he said.
"So far, there are no reported casualties or damages. We are now monitoring the shores for any rough movement."
In the municipality of Hinatuan, about 25 kilometers north of Barcelona, local disaster officer Jerome Ramirez saw appliances "moving for around 30 seconds" from the strong shaking.
Ramirez said there had been no reports of injuries or damage in coastal communities in the area.
"Now we are just monitoring for possible aftershocks," Ramirez told AFP by telephone.
Earthquakes regularly strike the Philippines, which sits along the Pacific Ring of Fire, an arc of intense seismic and volcanic activity that stretches from Japan through Southeast Asia and across the Pacific basin.
Most are too weak to be felt by humans, but strong and destructive quakes come at random with no technology available to predict when and where they will happen.
In December, a 7.6 magnitude quake struck off Mindanao, briefly triggering a tsunami warning.
That sent residents along the east coast of the island fleeing buildings, evacuating a hospital and seeking higher ground.
At least three people died.