An earthquake measuring magnitude 6.7 has struck Papua New Guinea, with an even bigger aftershock measuring 7.1.
The US Geological Survey recorded the quakes a day after a 6.9 tremor shook the nation.
People in the region were at one stage warned of the possibility of a "hazardous tsunami" but that alert has now been lifted.
Dr Roger Musson of the British Geological Survey told Sky News: "It's a very active seismic zone … it's produced much larger earthquakes than the one's we've had.
"The last big one that we had in this area, of magnitude 8, caused a tsunami that killed about 40 people."
There are no immediate reports of casualties or damage to property.
Rabaul, the town nearest where the earthquake hit, is on East New Britain Island.
It lies in the shadow of active volcano Mount Tavurvur - the town was destroyed 21 years ago when the volcano erupted.
