The earthquake , which was felt in Tokyo , had a magnitude of 7.4 , the Japan Meteorological Service said .
The earthquake , which was felt in Tokyo , was centred off the coast of Fukushima prefecture at a depth of about 10 km ( 6 miles ) .
The earthquake , which was felt in Tokyo , had a magnitude of 7.4 , the Japan Meteorological Service said , and was centred off the coast of Fukushima prefecture at a depth of about 10 km ( 6 miles ) .