The US-based Pacific Tsunami Warning Centre warned regional authorities to stay alert after reporting the temblor -- which it rated at 6.8 -- struck to the south of the island of New Britain in the Solomon Sea at 0125 GMT.
"Earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within 100 kilometres (60 miles) of the earthquake epicentre," the bulletin warned.
No immediate reports of casualties or damage were received after the quake, Geoscience Australia seismologist Phil Cummins told AFP.
The US Geological Survey rated the earthquake at a magnitude of 6.5 and said it struck at a depth of 58 kilometres, about 167 kilometres from Kandrian, New Britain.
In Rabaul, about 229 kilometres north-east of the quake's epicentre, David Loh, owner of the New Britain Lodge, reported strong earth tremors lasting up to 10 seconds.
"But no one got their feet wet," he told AFP.
Loh said he saw no change in the behaviour of Mount Tavurvur, a volcano whose activity had been subsiding since its spectacular eruption on October 7 forced residents to flee the town.
A series of aftershocks continued throughout the day, ranging from 5 to 5.4 in magnitude, the US Geological Survey reported.

Copyright AFP (Agence France-Presse), 2006