A strong earthquake of 6.4-magnitude on the ritchter scale shook northeast Japan's Fukushima prefecture at 3.54 a.m. local time but there were no immediate reports of casualties or major damages. Japan Meteorological Agency and the US Geological Survey said the quake was centred around 100 kilometres south-southeast of Fukushima city, at a depth of about 40 kilometres but there was no immediate threat of a Tsunami. The quake also caused no new damage to the Fukushima Daiichi nuclear plant, which was crippled by a massive 9.0 magnitude quake and tsunami on March 11 which left about 20,000 people dead or missing and triggered an atomic crisis at the nuclear plant.