A powerful 7.3 magnitude earthquake has shaken off the coast of Fukushima in northern Japan, triggering a tsunami advisory.
The Japan Meteorological Agency said the quake struck 60 kilometers below the sea on Wednesday evening.
The quake shook large parts of eastern Japan, including Tokyo, where buildings shook violently.
There are no immediate reports of casualties or damage.
The agency issued a tsunami advisory for up to a meter sea surge in parts of Miyagi and Fukushima prefectures.
NHK national television said the tsunami might have reached some areas already.
The Tokyo Electric Power Company Holdings, which operates the Fukushima Daiichi nuclear plant that suffered multiple meltdowns following the 2011 quake and tsunami that destroyed its cooling systems, said workers were checking for any possible damage.
The region is part of northern Japan that was devastated by a deadly 9.0 quake and tsunami 11 years ago that also caused nuclear plant meltdowns.
Wednesday’s quake came only days after the area marked the 11th anniversary of the disaster in March 2011.
A powerful 7.3-magnitude quake jolted east Japan on Wednesday night, rattling the capital Tokyo and prompting a tsunami advisory for parts of the northeast coast, the Japan Meteorological Agency said.
The quake was centred off the coast of the Fukushima region at a depth of 60 kilometres (37 miles).
Shortly after it hit at 11:36 pm (1436 GMT) an advisory for tsunami waves of one metre was issued for parts of the coast.
There were no immediate reports of damage or injuries, but at least two million households were left without power, including 700,000 in Tokyo, electricity provider TEPCO said.
Regional train company JR East said it was experiencing significant disruption to its operations. Japan sits on the Pacific “Ring of Fire”, an arc of intense seismic activity that stretches through Southeast Asia and across the Pacific basin.
The country is regularly hit by quakes, and has strict construction regulations intended to ensure buildings can withstand strong tremors.
But it remains haunted by the memory of the 2011 undersea quake in northeastern Japan that triggered a deadly tsunami and unleashed the Fukushima nuclear accident.