At least 41 people were injured, seven of them severely, by a magnitude-6.7 earthquake that struck Nagano Prefecture and surrounding areas late Saturday night, local authorities said Sunday.
Injuries were reported in the city of Nagano, the prefectural capital, and the ski-resort village of Hakuba, where more than 80 people spent the night in an evacuation shelter.
The quake hit at 10:08 p.m. at a depth of 5 km. It measured a lower 6 to 7 on the Japanese seismic scale in northern parts of Nagano and lower 5 in neighboring Niigata Prefecture, the Meteorological Agency reported. No tsunami alert was issued.
Among the seven people seriously injured, two were in the city of Nagano, four in Hakuba and one in the village of Matsukawa, the National Police Agency reported. Many of them sustained broken bones when their houses collapsed.
According to the Nagano Prefectural Government, at least 34 houses were razed in Hakuba and the nearby village of Otari, while 20 houses were severely damaged in Otari.
The quake caused blackouts in at least 200 households in the affected areas, according to NHK.
The prefectural government applied the disaster relief law to Hakuba and Otari as well as the village of Ogawa.
On Sunday, a Ground Self-Defense Force team joined in rescue operations with local police and firefighters.
The Prime Minister’s Office set up a crisis management center at 10:10 p.m. Saturday night to gather information and enact necessary measures, and Prime Minister Shinzo Abe instructed government ministries and agencies to use all necessary resources to respond, officials said.
Hakuba, which hosted events in the 1998 Winter Olympics, appeared to be one of the hardest-hit municipalities. The NPA said 21 residents of the village were trapped underneath collapsed houses, but that all had been rescued.
In addition to the collapsed houses, many buildings were severely damaged and seventeen residents were injured, local and national disaster agencies said. More than 100 homes in Hakuba were cut off from the water supply, prompting the village to provide water tankers.
Ryo Nishino, a restaurant owner in Hakuba, told NHK that he had “never experienced a quake that shook so hard. The shaking was enormous.”
“I was sleeping on the second floor when the quake occurred,” said Satoshi Yoshida, 50, a Hakuba resident who spent the night in an evacuation shelter with his family members. “All I could do was hide under a futon.”
Tokyo Electric Power Co. said no abnormalities were immediately apparent at its gigantic Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture. The plant, the largest atomic energy complex in the world, has remained offline since the Great East Japan Earthquake of March 2011.
Bullet trains on the Tohoku, Yamagata, Akita, Joetsu and Nagano shinkansen lines halted services shortly after the quake. All but the Nagano line resumed bullet train services about an hour later. On Sunday, services on that line went back to normal as well.
A total of 53 aftershocks had been recorded as of 11 a.m. Sunday, the Meteorological Agency’s earthquake and tsunami division said, among them a powerful jolt at 10:37 p.m. that measured a lower 5 on the intensity scale.
The agency warned of further aftershocks and urged residents to watch out for landslides. The same area was struck by a magnitude-6.7 temblor the day after the massive offshore temblor of March 11, 2011.
The agency meanwhile revised down the magnitude of Saturday night’s quake from its initial estimate of 6.8. Authorities on Sunday morning also reduced the tally of injured people after earlier reporting that over 50 had been wounded.
An official of Ogawa, which registered lower 6, said he experienced powerful jolts for about 20 seconds that sent books flying off shelves, NHK reported.
Chief Cabinet Secretary Yoshihide Suga told reporters shortly before midnight Saturday that the government had dispatched an advance team from the GSDF to the hardest-hit areas in northern Nagano. “We are doing all we can,” Suga said. “I want to ask affected people to help each other and act calmly.”
The Meteorological Agency held a news conference after midnight Saturday, urging caution over the possibility of further landslides and damage. The agency said people should be prepared for aftershocks that could last about a week.
“Further damage could occur to houses that were weakened by the initial earthquake,” an agency official said.