A major earthquake with a magnitude 7.7 struck off Papua New Guinea on Monday, official monitors said, and a tsunami warning was issued soon after.

The epicentre of the 33 km deep quake was near the town of Rabaul in the northeast of Papua New Guinea, the US Geological Survey (USGS) said.

The Pacific Tsunami Warning Center in Hawaii said "hazardous tsunami waves are possible for coasts located within 1,000 km of the earthquake epicentre along the coasts of Papua New Guinea and the Solomon Islands".

Tsunami waves reaching 1-3 metres (3-9 feet) above the tide level are possible along some coasts of Papua New Guinea, said the center.

No destructive, Pacific-wide tsunami was expected, it said. "Persons located in threatened coastal areas should stay alert for information and follow instructions from national and local authorities," it added.

Rabaul, a town on East New Britain Island, lies in the shadow of Mount Tavurvur, an active volcano. Rabaul was destroyed in 1994 during a severe eruption. - Reuters