The quake struck at a depth of 10 kilometres (6.2 miles) around 81 kilometres from the town of Angoram, it said, revising an earlier depth and distance as well as an earlier magnitude of 6.6.

The US tsunami warning agency said there was "no tsunami threat from this earthquake".

Earthquakes are common in Papua New Guinea, which sits on top of the seismic "Ring of Fire" -- an arc of intense tectonic activity that stretches through Southeast Asia and across the Pacific basin.

Although they seldom cause widespread damage in sparsely populated areas, they can trigger destructive landslides.