An earthquake with a preliminary magnitude of 5.7 struck Iwate Prefecture early Friday morning, the Meteorological Agency said. It said there was no risk of tsunami.
Firefighters said a woman in her 70s in the prefectural capital Morioka was hurt after falling following the quake and a woman in her 60s suffered a shoulder injury. Neither of the injuries was serious, they said.
Utilities reported no anomalies at the four nuclear power plants and one nuclear fuel reprocessing plant in neighboring prefectures, while East Japan Railway Co. said its railway network remained unaffected.
The 3:32 a.m. temblor struck off the coast at a depth of around 88 km. In the city of Morioka it registered lower-5 on the Japanese seismic intensity scale of 7, the agency said. (The agency adjusted its measurement of the time and magnitude slightly from its initial bulletin.)
The agency's intensity scale table describes a lower-5 quake as typically shaking hanging objects such as lamps violently and moving unsecured furniture. People would feel the need to hold on to something stable, it says.
Lower intensity levels were logged in other areas, with 4 marked in neighboring Aomori Prefecture in addition to parts of Iwate. Intensity 3 was registered in Hokkaido, Aomori, Miyagi, Akita and Iwate.
Tohoku Electric Power Co. said no abnormalities were found at the Higashidori nuclear power plant in Aomori or the Onagawa plant in Miyagi Prefecture.
Tokyo Electric Power Co. said no new anomalies were reported at either the Fukushima No. 1 plant, which was crippled by the 2011 quake and tsunami, or the Fukushima No. 2 plant.
Japan Nuclear Fuel Ltd. reported no unusual developments at its fuel reprocessing facility.
JR East said there was no impact on its train services in the region. It was planning to operate services including the Tohoku, Akita and Yamagata shinkansen normally on Friday.