A powerful earthquake rattled Papua New Guinea on Thursday, the fourth strong quake to hit the South Pacific island nation in a week. The temblor prompted officials to issue a local tsunami warning, but it was lifted shortly afterward with no immediate reports of damaging waves.

The 7.1-magnitude quake struck about 150 kilometres southwest of the town of Panguna on Bougainville Island at a depth of 23 kilometres, the U.S. Geological Survey reported.

The Pacific Tsunami Warning Center said tsunami waves of up to 1 metre were possible within 300 kilometres of the epicenter on the coast of Papua New Guinea. The agency lifted the warning about an hour later.

There were no immediate reports of damage, said Chris McKee, assistant director of the Geophysical Observatory in the capital, Port Moresby. Because the epicenter was so far offshore, the chance of serious damage on land was less likely, he said.

“It’s not a particularly strong earthquake in global terms, but it could still have generated a tsunami, so it’s a bit too uncertain at this stage to be sure,” he said.

Thursday’s quake was located in a different area of Papua New Guinea than the previous three temblors that rattled the region over the past week, and was therefore an unrelated event, McKee said.

Gumu Pala, an officer with the National Disaster Center, said staffers were trying to reach their colleague in Bougainville for an update from the ground. So far, they had not made contact with anyone from the region, as communications were spotty.

Papua New Guinea sits on the Ring of Fire, the arc of seismic faults around the Pacific Ocean where earthquakes are common