TOKYO (AFP) - Japan has issued tsunami alerts in five eastern prefectures after a 7.3-magnitude earthquake struck off its coast on Saturday morning, the Kyodo news agency said, quoting the Japan Meteorological Agency.

Workers at the crippled Fukushima nuclear plant were "ordered to evacuate from the waterfront", the agency reported, also quoting the Tokyo Electric Power Company as saying no new abnormalities had been found at the power station.