A strong earthquake has struck Papua New Guinea's northern coast, causing residents who feared a tsunami to seek higher ground.

The quake, which the US Geological Survey says had a 6.8 magnitude, reportedly lasted for three minutes.

No tsunami warning has been issued and there were also no reports of serious damage or injuries.

It struck at about 08:55 local time (22:55 GMT Tuesday), with an epicentre 19km (11 miles) east of Aitape town.

The coastal town of Aitape was devastated in 1998 when a huge earthquake triggered a tsunami that left more than 2,000 people dead.

No tsunami warning was issued, but the Pacific Tsunami Warning Center said a quake this strong could sometimes generate local tsunami waves within 100km of the epicentre.

"Authorities in the region should be aware of this possibility and take appropriate action," it said.

An eyewitness told ABC News that many people sought higher ground after the earthquake struck.

"They were frightened maybe the sea will come up," Max Kamave said.