According to the Japan Meteorological Agency, the quake struck off Honshu at 5:59 on Tuesday morning local time (20:59 GMT).
The agency has issued a warning over a possible 1-to-3-meter tsunami wave which could hit the country’s northeastern coast, where the Fukushima Daiichi nuclear power plant is located. The plant was the location of one of the world's worst nuclear incidents.
"Please do not think that you are safe. Please evacuate to high grounds," the network said. "Please think about the worst-case scenario and evacuate right away," read a warning announced by Japan’s state broadcaster NHK.
The US Geological Survey announced the quake’s magnitude at 6.9, and noted that it stroke 37 kilometers east-southeast of Namie off the country's east coast at a depth of 11.4 kilometers.
A spokesperson for Tokyo Electric Power, known as Tepco, announced that the cooling system for a used nuclear fuel storage pool at a reactor at its Fukushima Daini Plant had been slightly damaged during the quake, but was quickly restored.
There have been no other reports of damage or injuries, despite the quake managing to shake buildings in Tokyo.
On March 11, 2011, a huge tsunami, caused by a nine-magnitude earthquake, wreaked heavy damage on the Fukushima nuclear plant’s cooling systems that led to thousands of deaths, three meltdowns and the release of vast amounts of radiation into the surrounding environment.
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