A powerful 7.5-magnitude earthquake took place around 150km south of the town of Rabaul in Papua New Guinea on Tuesday, the United States Geological Survey reported.
The Pacific Tsunami Warning Centre said a Pacific-wide tsunami danger reaching as far as Hawaii was not expected.
The quake was felt strongly in Rabaul city with water splashing out of a swimming pool - Susan McGrade, owner of the Rabaul Hotel in Rabaul, told Reuters - but there were no immediate signs damage felt.
The US Geological Survey also reported an aftershock of magnitude 5.9, hitting 109km southwest of Kokopo, the capital of the East New Britain province of Papua New Guinea, at a depth of 65km.
Hazardous tsunami waves are possibly within 300 km of the epicentre, said the Pacific Tsunami Warning Centre, reporting no signs of immediate waves being seen.
"The earthquake is offshore and the nearby land areas are fairly sparsely populated," said Chris McKee, assistant director of the Geophysical Observatory in Port Moresby, Papua new Guinea’s capital.