ISTANBUL 

A strong 6.6 magnitude earthquake struck northern Papua New Guinea on Tuesday, according to the US Geological Survey (USGS).

The USGS originally reported a magnitude of 6.7, but later revised it down to a 6.6.

The quake originated at a depth of 99.4 kilometers (61.7 miles), 26 kilometers (16.1 miles) west of Lae, the coastal capital of the country’s Morobe province

Lae, with a population of 76,255, is the country’s second-largest city.

There were no immediate reports of damage or casualties.

The US Geological Survey did not issue any tsunami warning after the jolt, and both the Philippines and Australia have reported no tsunami danger to their countries.

Papua New Guinea lies along the Pacific "Ring of Fire," where most of the world's earthquakes and volcanic activity occur.