Japan's meteorological agency said that, within two hours, large tsunamis washed ashore into dozens of cities along a 1,300-mile stretch of the country's eastern shore - from the northern island of Hokkaido to central Wakayama prefecture. Prime Minister Naoto Kan said the quake caused "major damage in broad areas" and the government is preparing to send troops to the quake-hit areas to help relief efforts. Several nuclear plants along the coast were partially shut down, but there were no reports of any radioactive leakage.

TV footage showed waves of muddy waters sweeping over farmland near the city of Sendai, carrying buildings, some on fire, inland as cars attempted to drive away. Fires spread through a section of the city, public broadcaster NHK reported. Officials are trying to assess damage, injuries and deaths but had no immediate details. Police said at least one person was killed in a house collapse in Ibaraki prefecture, just north-east of Tokyo.

A large fire erupted at the Cosmo oil refinery in Ichihara city in Chiba prefecture near Tokyo and is burning out of control, with 100ft flames whipping into the sky, while NHK showed footage of a large ship being swept away by the tsunami and ramming directly into a breakwater in Kesennuma city in Miyagi prefecture. In central Tokyo, trains were stopped and passengers walked along the tracks to platforms. NHK said more than four million buildings are without power in Tokyo and its suburb