No deaths have been attributed to the quake that occurred at 11:07 p.m. Saturday, registering upper 6 on Japan's seismic intensity scale of 7 in parts of Fukushima and Miyagi prefectures, the government said. No tsunami accompanied the temblor.

Injuries were reported in Fukushima and Miyagi prefectures and six others, including Chiba, Kanagawa and Saitama, all neighboring Tokyo. The quake was felt in several other areas including the capital.

Water in a spent nuclear fuel pool spilled over at the Fukushima Daiichi Power plant, which suffered nuclear meltdowns triggered by a massive earthquake and tsunami event that hit the region 10 years ago, but it has not leaked, according to its operator Tokyo Electric Power Company Holdings Inc.

Other nuclear utilities have reported no irregularities so far.

Prime Minister Yoshihide Suga said at a meeting of Cabinet members in the morning the government has received reports of many injuries but no deaths and urged people to stay alert.

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"We want people to take action swiftly without letting their guard down by paying close attention to information provided by local authorities," said Suga, noting quakes of upper 6 on the seismic intensity scale could happen over the next seven days or so.

The blackouts, which affected about 900,000 households at one point, were largely resolved by the morning.

While the first batch of novel coronavirus vaccines manufactured by Pfizer Inc. arrived in Japan on Friday, Chief Cabinet Secretary Katsunobu Kato said the U.S. pharmaceutical giant has given assurances they have not been affected by the blackouts and are being stored at the required temperature.

Around 70 evacuation centers have been set up in Fukushima Prefecture and about 200 people are taking shelter, according to the Fukushima prefectural government.

The local government requested the central government dispatch the Ground Self-Defense Force to help supply water to residents.

Miyagi and Fukushima prefectures continued to experience water supply issues, with about 5,000 households in the former experiencing supply cuts.

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A landslide occurred along the Joban Expressway in Soma, Fukushima Prefecture, prompting East Nippon Expressway Co. to close the section between the Iwaki interchange in the prefecture and the Watari interchange in Miyagi Prefecture.

Heavy equipment had been dispatched to remove large boulders and soil which blocked all lanes.

East Japan Railway Co. said Tohoku shinkansen bullet train services between Nasushiobara Station in Tochigi Prefecture and Morioka Station in Iwate Prefecture have been suspended and will remain so throughout Monday after poles in several locations from which overhead wires are suspended were found to be bent.

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The partial suspension of services on the Tohoku shinkansen prompted Japan Airlines Co. to operate special flights connecting Tokyo's Haneda airport and Aomori airport in the northeast.

The Akita shinkansen between Tokyo and Akita, in Japan's northeast, will also halt services through Monday.

The Japan Meteorological Agency said the quake was felt in wide areas of Japan including the northernmost prefecture of Hokkaido and in the Chugoku region, containing Hiroshima, in western Japan.