Tsunami warnings have been lifted in Fukushima and the surrounding coastal region after a 7.1 magnitude earthquake struck 320km off the coast of Japan.
Tremors could be felt some 480 kilometres away in Tokyo.
A predicted one-metre high wave measured just 30cm when it hit land.
The quake struck at 2.10 am local time and many workers at the Fukushima nuclear power plant were evacuated to higher ground, though there were no immediate reports of damage or a change in radiation readings.
The plant’s nuclear reactors were damaged when an earthquake and tsunami with 40 metre high waves struck in 2011.
The disaster led Japan to close all but two of its 50 reactors and the company responsible for the plant is still battling to contain the damage.