A massive 8.9-magnitude earthquake hit Japan on Friday, unleashing a monster 10-metre high tsunami that sent ships crashing into the shore and carried cars through the streets of coastal towns.

Many injuries were reported from Pacific coastal areas of the main Honshu island and the capital Tokyo, police said, while TV footage showed widespread flooding in the area. One person was confirmed dead.

A powerful 10-metre (33 feet) wall of water was reported in Sendai in northeastern Miyagi prefecture, media reported after a four-metre wave hit the coast earlier.

Helicopter footage showed massive inundation in northern coastal towns, where floods of black water sent shipping containers, cars and debris crashing through towns.

Mud waves were shown racing upstream along the Natori river in Sendai city, blanketing farm fields.

In the capital, where millions evacuated strongly swaying buildings, multiple injuries were reported when the roof of a hall collapsed during a graduation ceremony, police said.

Plumes of smoke rose from at least 10 locations in city, where four million homes suffered power outages. Port areas were flooded, including the carpark of Tokyo Disneyland.

AFP