A 6.2-magnitude earthquake struck Papua New Guinea on Monday, the US Geological Survey said, but there were no immediate reports of damage.
The quake hit 115 kilometres (72 miles) northeast of Mount Hagen in the western highlands, the Pacific nation's third largest city, at a depth of 77 kilometres.
Geoscience Australia said it could have been felt in the city, but it was too far away and too deep to cause much damage.
Strong earthquakes 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.
A giant tsunami in 1998 killed more than 2,000 people near Aitape, on the country's northwest coast.