Tokyo (CNN) -- Authorities on Friday blamed three deaths and more than 130 injuries on a fresh earthquake that struck northern Japan a day earlier, shaking up a region already devastated by March's historic temblor.
The dead included an 85-year-old man who collapsed and died while trying to get to a shelter with his family and a 79-year-old man who was reported dead on arrival at the Red Cross hospital in the coastal city of Ishinomaki, doctors there reported.
Further inland, in Yamagata Prefecture, a 63-year-old woman died after a power outage caused by the quake stopped her oxygen, the prefecture's government told CNN.
Another 132 people were injured, 17 of them seriously, according to Japan's National Police Agency.
The Japan Meteorological Agency rated the Thursday quake a magnitude 7.4, while the U.S. Geological Survey put it at 7.1. It was considered an aftershock from the magnitude 9 quake and tsunami that struck nearby March 11, leaving more than 12,700 dead and 14,700 missing to date.
The Geological Survey said the quake was centered 66 kilometers (41 miles) from Sendai, one of the areas worst hit by last month's 9.0-magnitude quake, and 333 kilometers (207 miles) from Tokyo. It caused noticeable shaking in the capital for about a minute.
The new quake struck shortly after 11:30 p.m. Thursday (10:30 a.m. ET), closer to the coast than the March 11 disaster. It triggered a tsunami warning for one section of the coast and advisories for others, but the advisories were lifted about 90 minutes later.
Japanese nuclear regulators said no additional damage was reported at the Fukushma Daiichi nuclear power plant, where workers have been battling to keep overheating reactors under control since the March 11 quake. Workers evacuated the plant when the quake hit, but water continued flowing into the reactors, the Tokyo Electric Power Company told reporters.
But at the Onagawa nuclear plant, about 140 kilometers (88 miles) to the north, the latest rumbles caused several small leaks of radioactive water that totaled about 15 liters (3.9 gallons), the Sendai-based Tohoku Electric Company reported.
The leaks came from pools housing spent fuel from the plant's three reactors, which have been shut down since the March 11 earthquake, Tohoku Electric said. Their radioactivity was far below the threshold that posed a threat to human health, according to data released by the company.
A handful of roads were damaged as well as a few homes. About 4 million homes remained without power, police said, and water and train services were disrupted in some places.
A Japanese researcher said Friday that residents in eastern Japan, including Tokyo, can expect more such aftershocks in the coming months.
"We should not be surprised to have magnitude-7 level aftershocks even a year afterward anywhere as wide as east Japan in the wake of such mega-quake of magnitude 9," said Satoko Oki of the Earthquake Research Institute of Tokyo University.
CNN's Kyung Lah, Yoko Wakatsuki and Noriaki Kawai contributed to this report.
'''Po czwartkowym trzęsieniu ziemi doszło do wycieku wody chłodzącej w elektrowni atomowej Onagawa w północno-wschodniej Japonii. Przedstawiciele operatora elektrowni zapewniają, że dookoła elektrowni nie zarejestrowano zwiększonego poziomu promieniowania.'''
left Podczas konferencji prasowej w piątek rano czasu japońskiego przedstawiciele firmy Tohoku Electric Power, która zarządza elektrownią atomową Onagawa poinformowali, że nastąpił wyciek wody ze zbiorników w których składowane jest zużyte paliwo jądrowe z dwóch reaktorów tej elektrowni.

Według informacji operatora w elektrowni z basenu chłodzącego na podłogę wylało się około 3,8 litra wody. 

Wczoraj, wkrótce po trzęsieniu ziemi Japońska Agencja Bezpieczeństwa Nuklearnego poinformowała, że w elektrowni atomowej Onagawa nie działają dwie z trzech jednostek zasilania zewnętrznego. Według informacji operatora elektrowni dziś rano została przywrócona jedna z jednostek.

Tymczasem przedstawiciele Tokyo Electric Power Co podczas konferencji prasowej w Piątek rano poinformowali, że nie pojawiły się żadne nowe nieprawidłowości w działaniu reaktorów elektrowni Fukushima Daiichi. 

Wstrząsy jakie nawiedziły w czwartek Japonię miały siłę 7,1 w skali Richtera i zostały określone jako wstrząsy wtórne po tragicznym w skutkach trzęsieniu ziemi z 11 marca. W wyniku wczorajszych wstrząsów zmarły prawdopodobnie 3 osoby a około 140 osób zostało rannych.