A magnitude-5.5 earthquake hit the Kanto region Monday evening, shaking northern Ibaraki Prefecture with an intensity of lower 5 on the Japanese scale and 4 in wide areas in the region, the Meteorological Agency said. No tsunami warning was issued.
The focus of the 9:23 p.m. quake was in southern Ibaraki Prefecture, and its depth was estimated at around 42 km, the agency said.
In Omitama, Ibaraki Prefecture, it registered lower 5 on the Japanese seismic scale to 7, indicating shaking strong enough to frighten many people and make them feel the need to hold onto something stable.
An 8-year-old boy in Tsukuba broke his left elbow when he dived out of bed out of surprise at the shaking, firefighters said.
Although bullet trains and some other lines were temporarily halted, services were quickly resumed, railway officials said.
No damage was reported at airports, officials said.
Nuclear power stations in Ibaraki observed no abnormalities, their operators said.
The earthquake was felt in Tsukuba, Ibaraki Prefecture, where science and technology ministers from the Group of Seven nations were meeting through Tuesday.
Japanese officials rushed to make sure the ministers were safe.
“This is huge,” shouted a police officer as he dashed into the building, according to a Cabinet Office official describing the scene at the time of the temblor.
The official expressed hope that the quake is not a precursor to something bigger. Two deadly quakes in Kyushu last month remain fresh in the nation’s mind.
Elevators where the ministers were staying temporarily shut down. Hotel guests were seen looking out of the building’s windows.
Science minister Aiko Shimajiri was among the ministers taking part in the event.
Residents of areas that experienced strong shaking should prepare for further quakes as high as 4 on the Japanese scale over the next two or three days, the Meteorological Agency said at a news conference shortly before midnight.