The colossal earthquake just before 08.00am local time (11.00pm BST). The earthquake hit near the town Bulolo, the United States Geological Survey (USGS) confirmed. The quake hit a depth of 127km (79 miles) under the surface.
As it stands, there have no reports of any casualties.
The Pacific Tsunami Warning Centre has not issued any tsunami warnings following the colossal quake.
As well as no reported casualties, there have been no reports of damage.
The quake hit a mountainous region of the country in the early hours of Tuesday morning.
READ MORE: Earthquake measuring 6.2 in magnitude rocks Papua New Guinea
Tuesday’s quake will be the second earthquake the country has suffered in the last 24 hours.
A smaller 5.5 magnitude earthquake struck just off the coast of the country on Monday afternoon.
The first earthquake hit new the town of Panguna, which is situated on Bougainville Island.
No casualties or damage was reported at the time.
READ MORE: Tsunami WARNING issued 20 years after Papua New Guinea disaster
The country lies in the notorious Pacific Ring of Fire.
Due to the amount of seismic activity and tectonic plates, the country is under constant threat of earthquakes.
Last year more than 150 died after a magnitude 7.5 earthquake struck.
At the time, it was the worst earthquake to hit the country.