A strong 6.6-magnitude earthquake struck off Papua New Guinea on Sunday, the US Geological Survey reported, but a tsunami warning was not issued and no major damage was expected.

The quake hit 105 kilometres (65 miles) west of Panguna, a town on Bougainville Island, at a depth of 64 kilometres, and some 677 kilometres 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 impoverished 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 35 kilometres 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 AFP.

"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."

In 1998, a giant tsunami triggered by a 7.1-magnitude earthquake killed more than 2,000 people near Aitape, on PNG's northwest coast.