Sydney: A 7.5-magnitude earthquake struck off the coast of Papua New Guinea today, US seismologists said, with "hazardous" tsunami waves possible in areas near the epicentre although no major damage was immediately reported.

The quake hit at a depth of 33 kilometres, some 55 kilometres from the nearest city of Kokopo on New Britain island and 787 kilometres from the capital Port Moresby, the United States Geological Survey said.