It has been revealed in the past hour that a tsunami warning is an effect after an earthquake with preliminary magnitude of 7.3 has struck off the coast of Fukushima prefecture in Japan.
According to reports in Japan a tsunami warning for waves of up to three meters (10 feet) has been issued.
The Japan Meteorological Agency says the quake struck around 6 a.m at a depth of 10 kilometers (6 miles).
This story is developing.