A magnitude 5.9 earthquake struck near Tokyo late on Thursday. It did not trigger a tsunami.
Meteorological Agency officials are warning of the possibility of quakes with a similar intensity over the next week or so.
The quake occurred at 10:41 p.m. Its focus was in Chiba Prefecture, east of Tokyo, at a depth of 75 kilometers.
The quake registered an intensity of 5 plus on Japan's seismic scale of zero to seven in Tokyo and Saitama.
The tremor was widely felt in and around the greater Tokyo area.
It disrupted public transit networks, stranding commuters who had been heading home.
The Chief Cabinet Secretary said more than a dozen people were injured, one of them seriously.
He said there are no reports of major blackouts, but many water leakages occurred due to broken water pipes.
Prime Minister Kishida Fumio set up a crisis management task force at his office to oversee the government's response.
Authorities reported dozens of injuries in the Tokyo area.
They say there are no reports of major damage.
The earthquake affected public transportation in the greater Tokyo area.
Officials say one train derailed after making an emergency stop in Tokyo's Adachi ward and at least three people were injured.
Railway officials say service on bullet train lines was suspended but resumed.
People were lining up at many stations in Tokyo to catch taxis after some local lines were halted after the quake.
Part of a wall of a building in Ueno in northern Tokyo collapsed but no injuries were reported so far.
Police officials at the scene were asking people to stay away from damaged area.
NHK footage showed black smoke coming from a window of a house in Saitama Prefecture near Tokyo.
No injuries have been reported so far.
Water pipes were ruptured in several affected places.
Water was seen gushing to nearby houses and sidewalks.
Officials say no abnormalities have been detected at nuclear-related facilities in Ibaraki and Kanagawa Prefectures near Tokyo.
Officials are warning residents to be cautious of structural damage that may have already occurred in the affected area.