A magnitude 6.4 tremor struck off the coast of Papua New Guinea early on Tuesday, US Geological Survey has said.

There is no tsunami warnings, seismologists said, adding the earthquake happened off the coast of Bougainville Island.

The epicenter of the quake was about 100 kilometers southwest of the town of Arawa, USGS said. It was a shallow tremor occurring at a depth of 32 kilometers.

The Pacific 'Ring of Fire' nation witnesses quakes quite often as it lies on an area where the friction between tectonic plates produces unusually high seismic activity.