At least 14 people have been killed in landslides and by collapsed buildings during a powerful earthquake in the remote Papua New Guinea highlands.

The 7.5 magnitude quake that rocked the region early on Monday also damaged mining and power infrastructure and led ExxonMobil Corp to shut its $US19 billion ($A27 billion) liquefied natural gas (LNG) plant, the country’s biggest export earner.

Two building collapses and a landslide killed 12 people in Mendi, the provincial capital of the Southern Highlands, said Julie Sakol, a nurse at Mendi General Hospital, where their bodies were brought to the morgue.

“People are afraid. The shaking is still continuing. There’s nowhere to go but people are just moving around,” she said.

Dozens of aftershocks rattled the area, including a 5.7 quake on Tuesday afternoon, the US Geological Survey reported.

Police in Mendi said 14 people were killed in the initial quake, including three in Poroma, south of Mendi.

“They were killed by landslides destroying families sleeping in their houses,” said Naring Bongi, a police officer in Mendi.

Provincial Administrator William Bando said more than 30 people were believed to have been killed in the rugged region, about 560km northwest of the capital, Port Moresby, the Papua New Guinea Post-Courier reported.

The PNG disaster management office said it was verifying the reports but it could take days to confirm a death toll.

ExxonMobil said communications with nearby communities remained down, hampering efforts to assess damage to facilities that feed the PNG LNG plant.

“Communications continue to be one of the most significant challenges,” the company said in an emailed statement.

Its partner, Oil Search, said a review of all of its facilities and infrastructure would take at least a week.