A 7.7-magnitude earthquake struck off the coast of Papua New Guinea Monday, US seismologists said, with "hazardous" tsunami waves possible within 1,000 kilometres (620 miles) of the epicentre.
The quake hit at a depth of 65 kilometres, some 54 kilometres from the nearest city of Kokopo Panguna on New Britain island and 789 kilometres from the capital Port Moresby, the United States Geological Survey said.
"Based on preliminary earthquake parameters... hazardous tsunami waves are possible for coasts located within 1,000 kilometres of the earthquake epicentre," the Pacific Tsunami Warning Centre said.