An earthquake of magnitude 7.6 has struck Papua New Guinea, reportedly damaging property and spreading panic among residents.
The US Geological Survey (USGS), which said the quake hit eastern Papua New Guinea at 9:46am local time on Sunday, issued a tsunami warning but subsequently said the threat "has now passed".
It did, however, note that there could still be "minor sea-level fluctuations in some coastal areas".
Shaking was felt widely in the country from towns near the epicentre to the capital of Port Moresby, about 480 kilometres away.
Images and video of damage to a university in the eastern highland town of Goroka showed large cracks appearing in walls and window awnings falling during the quake.
Locals in Lae and Madang, closest to the epicentre, said the shaking was much more vigorous than previous quakes.
"Very strong, everything was like sitting on a sea -- just floating," Hivi Apokore, a worker at Jais Aben Resort near Madang, said.
The quake struck at a depth of 61 kilometres, about 67 kilometres from the town of Kainantu, the USGS said.
Papua New Guinea sits on the Pacific "Ring of Fire", causing it to experience frequent earthquakes.
Geologist Renagi Ravu, who was meeting with colleagues at his home in Kainantu, said the quake lasted for around a minute.
He tried to stand up from his chair but couldn't maintain his balance and so ended up in a kind of group hug with his colleagues, while plates and cups crashed from his shelves to the ground.
His children, aged 9 and 2, had their drinks and breakfast spill over, but weren't injured.
Also on Sunday, an earthquake of magnitude 6.1 struck the Mentawai Islands off the western coast of Indonesia's Sumatra island on Sunday, the country's geophysics agency BMKG said.
There was no danger of tsunami or reports of serious injuries, local officials said.
Wires/ABC