A strong 6.8-magnitude earthquake rocked Papua New Guinea's north on Wednesday as seismologists warned there could be considerable damage in Aitape, where a giant tsunami in 1998 killed more than 2,000 people.
The quake, at a depth of just 13 kilometres (eight miles), hit 22km east of the town of Aitape on the Pacific nation's north coast, which has a population of around 8,000, at 8.55am (2255 GMT Tuesday), the US Geological Survey said.
No destructive tsunami warning was issued by the Pacific Tsunami Warning Center but it cautioned that earthquakes of this size could sometimes generate local tsunami waves within 100 kilometres of the epicentre.
"Authorities in the region should be aware of this possibility and take appropriate action," it said.
A giant tsunami in 1998 killed more than 2,000 people near Aitape following an earthquake off the coast, with waves measured at up to 10 metres.
In that disaster, churches, schools and other buildings were swept away.
Geoscience Australia measured the quake at a depth of 20 kilometres and 30 kilometres from Aitape and said around 60,000 people would be in the exposure zone.
"This would include outlying local villages," seismologist Steve Tatham told AFP.
"At this stage we have heard nothing about the effect but it is quite large and there would have been a high level of shaking.
"There is the possibility of considerable damage. It certainly could bring buildings down."
The PNG Natural Disaster Center said it was still working on gathering feedback and had no concrete information so far. Police, ambulance and church officials in Aitape could not be reached by AFP.
Personnel at Wewak Hospital, about 150 kilometres from the coastal epicentre, said they felt the tremor but there was no damage to the building or any immediate reports of damage from the town of Wewak.
Hospital spokesman Morris Iuandu said there had been no news yet from Aitape and no casualties had presented to the emergency department in Wewak at this early stage.
"It was a strong one. This is a solid building -- not iron but solid -- and it was shaking," Iuandu told AFP.
He estimated that the swaying had lasted at least three minutes.
Quakes of such magnitude 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 6.6-magnitude quake struck the country's Bougainville Island on Sunday, but there were no reports of damage or injuries.