Updated

A strong earthquake has struck the South 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-6.4 quake struck Wednesday at a depth of 17 kilometers (10 miles). The epicenter is about 30 kilometers (18 miles) north of Rabaul on Papua New Guinea's island of New Britain.

The Pacific Tsunami Warning Center did not issue a tsunami alert and the Geophysical Observatory in the capital, Port Moresby, had not received any reports of damage or unusual wave activity.

Earthquakes are common in Papua New Guinea. The country lies on the "Ring of Fire" — an arc of earthquake and volcanic zones that stretches around the Pacific Rim.