The earthquake struck about 382 kilometers (237 miles) northeast of Tokyo at 2:46 p.m. (05:46 GMT) on Friday. A tsunami of four meter has hit Japan’s Pacific coast after the quake, AFP reported.
Waves have hurled ships and cars into the port town. A Japan TV broadcast has confirmed the magnitude and reported that many people have been injured.
A tsunami warning has been issued for Japan, Russia and the Mariana Islands.
The meteorological agency issued its top-level evacuation alerts for the entire coast, warning of a tsunami of up to six meters (20 feet).