A 7.6-magnitude earthquake hit off eastern Papua New Guinea on Sunday, with locals reporting damage to buildings near the coastal town of Madang and further inland.

The US Geological Survey, which reported the quake, 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".

Power outages and damage to buildings were reported in parts of Papua New Guinea, with shaking felt widely in the country from towns near the epicentre to the capital of Port Moresby, about 300 miles (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, told AFP 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 (38 miles), 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.

In neighbouring Indonesia in 2004 a 9.1-magnitude quake triggered a tsunami that killed 220,000 throughout the region, including about 170,000 in Indonesia.