An earthquake of magnitude 7.5 has struck Papua New Guinea, according to the US Geological Survey.
The quake had a depth of 35 kilometres, hitting at about 4am local time, according to the USGS, RNZI reports.
The quake struck in the heart of mainland PNG in Southern Highlands province. There were no immediate reports of damage.
According to the Pacific Tsunami Warning Center, the quake did not present a regional tsunami threat.
About a half an hour later an earthquake with a magnitude of 5.5 struck in the same area with a depth of 39 kilometres.
The 7.5 quake is understood to have been felt in neighbouring provinces including Southern Highlands, Enga, Western Highlands and Western.
However the mobile phone network in this wider region has been disrupted, frustrating attempts by people in other parts of PNG to gauge initial reports of damage from the quake.
The epicentre of the quake is located in a rugged region near Mt Sisa, which is close to key infrastructure for PNG’s ExxonMobil-led LNG gas project.
A spokesperson from Exxon said all of its employees and contractors at its Hides gas facilities have been accounted for and are all safe.
She says that as a precaution, ExxonMobil PNG Limited has shut in its Hides Gas Conditioning Plant to assess any damages to its facilities.