An earthquake of 6.7 magnitude struck off the coast of Papua New Guinea, the United States Geological Survey has said.
There were no immediate reports of tsunami warnings or damage after the reports on Sunday.
The quake hit 105km west of Panguna, a town on Bougainville Island, at a depth of 64km, and some 677km west of the Solomon Islands' capital Honiara, it said.
"A destructive tsunami was not generated based on earthquake and historical tsunami data," said the Pacific Tsunami Warning Center.
Quakes of such magnitude are common in PNG, which sits on the so-called Pacific "Ring of Fire", a hotspot for seismic activity due to friction between tectonic plates.
Geoscience Australia measured the quake at a depth of 35km and said people on Bougainville would have felt it.
"It was a fair way out to sea but people would have got a pretty decent shake on the island," Geoscience seismologist Dave Jepsen told the AFP news agency.
"We are not expecting much damage. These sorts of quakes are frequent occurances in the region so people tend to be used to them and houses built to withstand them."