An earthquake struck northeastern Japan on Saturday, triggering a 1-metre tsunami and hitting areas devastated by the 2011 disaster.
The quake hit the coast of Miyagi prefecture at 6.26pm (0926 GMT) and had a magnitude of 7.2 at a depth of 60km, the Japan Meteorological Agency said.
There were no immediate reports of damage or injuries, but people were warned against going near the shore as the tsunami might have reached parts of the Miyagi coast already.
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 spokesperson 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.
Miyagi Prefecture was having power outages in some areas, according to the Tohoku Electric Power Network.
Service on the Tohoku Shinkansen bullet train had been halted, public broadcaster NHK 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. The electricity is on.”
Akira Wakimoto, a crisis management official in Tome town in Miyagi prefecture, said he was in his apartment when the quake struck and felt his room shake for a long time.
In the coastal city of Ofunato, Shotaro Suzuki, a hotel employee, said there was a temporary blackout and elevators stopped briefly, but power has been restored and there were no other problems.
“Our guests seemed worried at first, but they have all returned to their rooms, and our facility seems fine,” Mr Suzuki told NHK.
Footage from inside NHK’s Sendai bureau showed 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.
Japan marked this month the 10th anniversary of the 2011 9.0-magnitude earthquake and tsunami that triggered a nuclear meltdown in Fukushima and killed more than 18,000 people.
The country is among the world’s most seismically active areas, accounting for about 20 per cent of earthquakes that are magnitude 6 or greater globally.