An earthquake with a preliminary magnitude of 5.3 struck off Japan's Fukushima Prefecture on Thursday, the weather agency here said.According to the Japan Meteorological Agency (JMA), the temblor occurred at a depth of 60 km.An earthquake with a preliminary magnitude of 5.3 struck off Japan's Fukushima Prefecture on Thursday, the weather agency here said.According to the Japan Meteorological Agency (JMA), the temblor occurred at a depth of 60 km.