AKIPRESS.COM - A major earthquake with a magnitude of 7.7 has struck off Papua New Guinea, official monitors say, and a tsunami warning has been issued, media report Monday.

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 (USGS) said.

Mika Tuvi, an employee at the Rabaul Hotel near Kokopo, told the ABC the ground shook strongly for about five minutes but there does not appear to be any major damage.

The Global Disaster Alert and Coordination System said wave peaks of 50 centimetres were recorded in locations close to the epicentre two minutes after the quake struck.

The initial quake was also followed by a smaller 5.7 magnitude aftershock in the same area.