An earthquake of magnitude 7.1 struck 135km east of the town of Rabaul, on the eastern tip of Papua New Guinea's island of New Britain, at 3.39am on Friday, local time (0.39 Thailand time), the US Geological Survey said.
Although the quake was under the seabed at a relatively shallow depth of 10km, the Pacific Tsunami Warning Center said there was no threat of a tsunami.
A quake of magnitude 7.5 struck the rugged highlands of the Papua New Guinea mainland on Feb 26, killing more than 100 people.