The 6.9 magnitude quake (which was initally measured by the US Geological Survey as magnitude 7-point-3) struck near the village of Wau, just after one o'clock this afternoon, local time, at a depth of 85 kilometres.
The Pacific Tsunami Warning Centre says hazardous waves are possible within 300 kilometres of the epicentre, along the coast of PNG.
The epicentre is about two-hundred kilometres north of PNG's capital Port Moresby.