According to the US Geological Survey (USGS), the magnitude-7.5 earthquake struck at a depth of 35km in Komo-Magarima district.
It hit at 4am local time, according to the USGS.
The Pacific Tsunami Warning Center in Hawaii said there was no risk of a tsunami in the aftermath of the quake.
The mobile phone network in the region has been disrupted, frustrating attempts by people in other parts of PNG to gauge initial reports of damage from the quake.
However, local MP Manasseh Makiba said he received preliminary reports from ExxonMobil personnel, via their satellite phones, as well as people in his district on landline phones.
"The reports are coming that the earthquake was very huge, and there was some casualties. There were landslides and destruction of some properties and houses.
"And there were reports of some lives being lost ... about ten."
Mr Makiba said the National Disaster Office is expected to dispatch a team to the area to assess the damage.
The quake is understood to have been felt in neighbouring provinces including Southern Highlands, Enga, Western Highlands and Western.
About half an hour after the 7.5 quake, an earthquake with a magnitude of 5.5 struck in the same area at a depth of 39km.
Mining and Petroleum operations shut down
National Coordinator for the PNG Resource Governance Coalition said images filtering from the giant Ok Tedi copper mine, in Western Provence, indicated serious damage to roads and copper pipelines.
Martyn Namorong said pipelines carrying copper concentrate and mining waste have also been damaged, raising serious concerns about toxic spills into the environment and there are concerns about the integrity of the gas pipeline that runs from the highlands to Port Moresby.
Mr Namorong said the images he's seen from the area showed enormous land slips and twisted pipes.
"Well in terms of the photos they're showing major landslides. These are not small landslides they're massive landslides. The damage is very, very significant.
"The quake would have been really, really massive in terms of.. in fact what people are saying is it's probably the worst earthquake they've ever felt in their entire lives."
Mr Namorong said the company Oil Search released a statement to the Australian Stock Exchange confirming the shutdown of its production facilities in the highlands due to the quake.
The company said it was trying to confirm that all its staff have been accounted for.
The company said it was monitoring the impact of the quakes on the local communities and will assist the authorities where possible.
The area is the hub of PNG's LNG Project, in which Oil Search has a 29 percent stake.
The epicentre of the quake was located in a rugged region near Mt Sisa, which is close to key infrastructure for PNG's ExxonMobil-led LNG gas project.
Earlier, a spokesperson from Exxon told RNZ Pacific that all of its employees and contractors at its Hides gas facilities had been accounted for and are all safe.
She said that as a precaution, ExxonMobil PNG Limited had shut in its Hides Gas Conditioning Plant to assess any damages to its facilities.
Photo: Baundo Mereh /Facebook Caption: Landslide near the Ok Tedi Copper/Gold mine in Western Province