The quake struck off the eastern coast early this morning - triggering a tsunami of up to 50 centimetres in the Pacific coast.
Japan's Meteorological Agency's issued tsunami warnings for the prefectures of Hokkaido , Aomori and Iwate .
CNN's Hanako Montgomery says there have been reports of damage and injuries.
She says the chief cabinet secretary says there have also been fires and ambulance callouts in Aomori prefecture.
