Geoscience Australia said the aftershocks had ranged from magnitude-5 to 6.3.
Monday’s earthquake struck in the Southern Highlands province in the early hours of the morning, causing damage to buildings and landslides.
There are fears already-damaged buildings in towns like Mendi, the capital of Southern Highlands province which is home to more than 50,000 people, may not survive continuing aftershocks.
The director of PNG’s National Disaster Centre, Martin Mose, said communication networks were down and that was making it hard to assess the impact of the quake.
“We would have expected widespread damage,” he said.
“There have been unconfirmed reports coming through of a number of deaths and of course widespread damage.”
The government said it was sending response teams including defence personnel to the affected areas.
“The Papua New Guinea Defence Force has also been mobilised to assist with the assessment and the delivery of assistance to affected people as well as the restoration of services and infrastructure,” Isaac Lupari, the chief secretary to the Government, said in a statement.
Airports and hospitals were among the infrastructure and buildings believed to have been damaged.
“This earthquake – how can I describe it – it’s just something else, something I’ve never experienced,” said Philemon Kambu, a bank officer in Mendi.
“In the place I’m from, Pangia in the far south, houses have collapsed.”
A resident in Mendi said she feared “the ground might open up and swallow us” when her thatched roof collapsed.
“When we came out we barely recognised everything around us, nothing was familiar to us,” Agnes Kep told the Post Courier newspaper. “The house or tree that was there wasn’t there anymore.”
The governor of Hela province, Philip Undialu, told local media the damage was “extensive”.
“Our police station, courthouse, hospital – even private houses have been ripped apart or sunk into the ground,” Undialu said from the country’s capital, Port Moresby.
ExxonMobil said it had shut its Hides gas conditioning plant in Hela province and that it believed administration buildings, living quarters and a mess hall had been damaged.
It also said it had suspended flights into the nearby Komo airfield until the runway could be surveyed.
“Due to the damage to the Hides camp quarters and continuing aftershocks, ExxonMobil PNG is putting plans in place to evacuate non-essential staff,” the company said in an emailed statement.
PNG oil and gas explorer Oil Search said in a statement it had also shut production in the affected area.
Aid agencies said they were ready to help but were also awaiting more information. Udaya Regmi, the country head of the International Federation of Red Cross and Red Crescent Societies, said it had 20 volunteers on standby but that getting accurate information remained difficult.
The earthquake has reportedly also caused panic and damaged buildings across the border in West Papua but detailed reports are not available.
- PNC sources