Sydney: A 7.5-magnitude earthquake struck Papua New Guinea early on Monday, US seismologists said, but no tsunami warning was issued.

The quake's epicentre was around 90 kilometres south of Porgera in Enga province, according to USGS.

It wasn't immediately clear if there was damage. The Geological Survey website had 19 reports of feeling the quake, including some saying the shaking was violent.