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.A strong 6.2-magnitude earthquake also hit northeastern part of Japan today, but there was no tsunami warning or immediate reports of damage. The US Geological Survey said the quake struck 79 kilometres southeast of Sendai in Miyagi prefecture, around the same area as the giant March 11 earthquake and tsunami. The depth of the quake was 35 kilometres. The devastating March 11 disaster left about 22,000 people dead or missing and triggered an atomic crisis at the Fukushima Daiichi nuclear plant.