A strong earthquake has struck off the coast of the Pacific island nation of Papua New Guinea. There are no immediate reports of damage or injuries and no tsunami alert has been issued.
The U.S. Geological Survey says the magnitude-6.8 quake struck Monday 81 miles (131 kilometers) east of the town of Wewak at a depth of 10 miles (16 kilometers).
The Pacific Tsunami Warning Center did not issue a tsunami alert.
Papua New Guinea lies on the "Ring of Fire." The region is an arc of earthquake and volcanic zones that stretches around the Pacific Rim and where about 90 percent of the world's quakes occur.