Thousands of people have been ordered to higher ground after a major earthquake struck off the coast of Japan, prompting a tsunami warning for the coast of Fukushima Prefecture.
The quake, which Japanese authorities have measured at a magnitude of 7.4, hit off the coast of Fukushima on the island of Honshu, early Tuesday local time.
Residents of coastal areas of the nation's northeast have been urged to leave for higher ground.
Just after 9am (AEDT) a tsunami was reported to have reached Fukushima at Iwaki, with a number of small tsunami waves subsequently hitting the coast. The biggest tsunami wave recorded so far has been 1.4m at Sendai. There have been warnings that three-metre waves could reach land in coming hours.
Japanese media says that two people were "slightly injured" in the quake.
Fukushima Prefecture is north of Tokyo and in 2011 it was the site of a major previous nuclear catastrophe triggered by an earthquake and tsunami. The Tokyo Electric Power Company, which runs the stricken Fukushima nuclear power plant, said it restored a cooling system that briefly stopped after the quake, according to NHK.
Dramatic vision has emerged showing the quake in action, shaking buildings, streets and shops.
Speaking from Argentina, Japan's Prime Minister Shinzo Abe said the government would do in its power to help with the aftermath of the powerful quake.
More to come.