An earthquake has struck northeastern Japan, hitting areas devastated by the 2011 disaster, generating a tsunami of one metre and shaking buildings.
The quake, with a magnitude of 7.2, hit the coast of Miyagi Prefecture at 6.26pm (2026 AEDT) on Saturday at a depth of 60 kilometres, the Japan Meteorological Agency said.
All tsunami alerts were lifted about an hour later, broadcaster NHK said after warning the public not to go near the shore.
There were no immediate reports of deaths or injuries.
Tokyo Electric Power said it had found no irregularities at its Fukushima Daiichi nuclear plant - wrecked by the massive March 2011 quake that caused nuclear meltdowns and mass evacuations. A spokesman said there were also no irregularities at its nearby Daini facility.
There were no irregularities at Tohoku Electric Power Co's Onagawa nuclear plant, the nuclear regulator said in an email.
Service on the Tohoku shinkansen bullet train was halted, NHK said.
About 200 households in Kurihara city, Miyagi Prefecture, lost power because of the quake, the trade and industry ministry said.
"It was a really bad, long shaking from side-to-side. It was even longer than the quake last month, but at least the building here is all right," Shizue Onodera told NHK from the shop where she works in the city of Ishinomaki.
"Lots of bottles smashed on the floor," she said. "The electricity is on."
NHK footage from inside its Sendai bureau showing a plaque suspended from the ceiling shaking for about 30 seconds following the tremor. It did not report any items falling from shelves or any immediate damage.
The quake could be felt in Tokyo, about 400km south of the epicentre.