A strong earthquake has struck off the coast of the Pacific nation of Papua New Guinea. There are no immediate reports of damage or injuries and no tsunami alert was issued. The US Geological Survey says, today's tremor measuring 6.2 on the Richter struck 46 miles south of the town of Kavieng on the island of New Ireland. The Pacific island nation of Papua New Guinea lies on the “Ring of Fire”, an arc of earthquake and volcanic zones that stretches around the Pacific Rim and where about 90 per cent of the world's quakes occur.