An earthquake with a preliminary magnitude of 6.0 jolted a wide area of northeastern Japan early Tuesday, the weather agency said, with no tsunami warning issued, but there were reports of minor injuries.

The 4:24 a.m. quake registered lower 5 on the Japanese seismic intensity scale of 7 in areas including Hachinohe and Misawa in Aomori Prefecture, and Miyako and Kuji in Iwate Prefecture, according to the Japan Meteorological Agency.

A woman in her 70s in Hachinohe was taken to hospital after she fell out of bed and injured her left wrist, while a woman in her 80s injured her head as she fell upon standing up, according to local firefighters.

There were no reported injuries in Iwate Prefecture.

The agency warned that earthquakes with a seismic intensity of around a lower 5 could continue in affected areas for about a week.

The temblor measured 4 in many other areas of the two prefectures, including Higashidori, Morioka and Hanamaki, as well as Kesennuma in Miyagi Prefecture, according to the agency.

The epicenter of the quake was in northern Iwate Prefecture at a depth of about 71 kilometers, the agency said. It initially said the preliminary magnitude was 6.1 with a focus depth of 80 km.

No abnormalities were detected after the quake at the Onagawa or Higashidori nuclear power plants, located respectively in Miyagi and Aomori prefectures, the operator Tohoku Electric Power Co. said. Neither plant was operating at the time of the quake.

Japan Nuclear Fuel Ltd. said the quake did not affect the operation of its reprocessing plant in Rokkasho, Aomori Prefecture.

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