Tokyo, Apr 4 (Reporter) An earthquake with a preliminary magnitude of 6.0 struck off Japan's northeastern prefecture of Fukushima on Thursday, according to the country's weather agency. The temblor occurred at 12:16 p.m. local time (0316 GMT) at a depth of 40 km, measuring 4 on Japan's seismic intensity scale, which peaks at 7, said Japan Meteorological Agency (JMA). The epicenter was located off the prefecture at a latitude of 37.7 degrees north and a longitude of 141.9 degrees east. Tremors were also felt in central Tokyo. No casualties have been reported so far and the JMA has not issued tsunami warnings...////...