The 7.3 magnitude quake struck off the east coast of Japan just minutes ago, with warnings issued for an imminent three metre-high wave.
A tsunami has been spotted off shore and is currently approaching the east coast and is expected to hit the east coast of Japan shortly.
They said: "We have already observed a tsunami and expect the tsunami to come to the sea side."
The Japanese Meterological Agency has ordered several locations to "evacuate immediately" and get to higher ground.
They said in an emergency bulletin: "Tsunami Warning. Damage due to tsunami waves is expected.
The earthquake struck off the coast of Fukushima Prefecture. The BBC is reporting that it was 6.9 in magnitude. I would not expect much structural damage from a 6.9 earthquake given Japan's building codes. However, a tsunami is much more dangerous."Evacuate immediately from coastal regions and riverside areas to a safer place such as high ground or an evacuation building.