A 7.3-magnitude "aftershock" that hit eastern Japan is believed to be that of an earthquake 10 years ago.
"This earthquake is considered to be an aftershock of the 2011 off the Pacific coast of Tohoku Earthquake," Japan Meteorological Agency said in a press release following the earthquake on Saturday.
The most recent earthquake happened just weeks before the 10-year anniversary of the March 11, 2011 Tohoku quake that devastated Japan and triggered a massive tsunami that led to the world's worst nuclear crisis in a quarter of a century.
“Because (the 2011 quake) was an enormous one with a magnitude of 9.0, it’s not surprising to have an aftershock of this scale 10 years later,” Kenji Satake, a professor at the University of Tokyo’s Earthquake Research Institute, said, according to the Japan Times.
Late Saturday (local time), the earthquake shook Fukushima, Miyagi and other areas, including Tohoku.
Given the scale of the earthquake, the agency is warning similar earthquakes could occur in the coming days.
"In addition, although the aftershock activity of the Tohoku-Pacific Ocean Earthquake tends to decrease gradually as a whole, the number of earthquakes per year continues to be higher than before the Tohoku-Pacific Ocean Earthquake," the press release said.
"So please continue to be careful."
No serious injuries have been reported, though people in Miyagi, Fukushima, Ibaraki, Tochigi, Saitama and Chiba prefectures have been hurt, according to the Japan Times, and at least 950,000 homes lost power across the country.
Power outages were reportedly resolved on Sunday morning.
Government spokesperson Katsunobu Kato said some trains in northeastern Japan had stopped running and other damage was still being checked.
Video from public broadcaster NHK TV showed some pieces of a building wall had broken off and fallen to the ground, and pieces of glass were scattered at a store.
Items fell off shelves because of the shaking, NHK TV said.
NHK TV aerial footage showed a portion of a highway blocked by a landslide in Soma, a city in the Fukushima prefecture.
The extent of damage from the landslide was not immediately clear, Mr Kato said.
The Japan Meteorological Agency said the quake was centred about 55 kilometres beneath the ocean, changing it from the earlier estimate for 60 kilometres.
Prime Minister Yoshihide Suga headed into his office immediately after reports of the quake and a crisis centre was set up there. He said there were no reports of major injuries.
With Reuters and the Associated Press
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