A strong 6.4-magnitude earthquake struck off Papua New Guinea on Monday but there were no immediate reports of casualties or damage, a spokesman for Geoscience Australia said.
The temblor hit about 80 kilometres (50 miles) offshore from New Ireland at a depth of about 60 kilometres and was unlikely to generate a tsunami, Jonathan Bathgate told AFP.
"Based on the magnitude of the earthquake it is not one we would consider to be tsunamigenic," he said.
Papua New Guinea is home to many active volcanoes and sits on the Pacific "Ring of Fire" where several tectonic plates collide. The region is frequently rocked by earthquakes.