PORT MORESBY - A POWERFUL 6.7-magnitude earthquake shook Papua New Guinea overnight, waking people from their sleep but causing no damage or tsunami, an official told AFP on Wednesday.

A spokesman for Port Moresby Geophysical Observatory said the offshore quake, which triggered a local tsunami alert, was felt strongly in eastern districts.

The quake struck at struck at 1219 am (2219 Singapore Time) at a depth of 35 kilometres and 179 kilometres off eastern PNG's Rabaul township.

'It was felt strongly in Rabaul but at this point we don't have any report of any damage,' the official said.

The Pacific Tsunami Warning Centre earlier warned that 'earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a hundred kilometres of the earthquake epicentre'.

Papua New Guinea sits on the so-called Pacific 'Ring of Fire', where continental plates meet. The region is frequently rocked by earthquakes. -- AFP