A strong earthquake, with an estimated magnitude of 6.0, jolted central Tokyo on Monday morning.
The quake, which struck at about 5:18 a.m., measured lower 5 on the Japanese seismic intensity scale of 7 in Chiyoda Ward, Tokyo.
According to the Japan Meteorological Agency, the focus is about 162 kilometers below the seafloor off Izu Oshima island.
The quake unlikely will cause tsunami, the agency said.
The quake registered an intensity of 4 in other areas of Tokyo and some areas in Kanagawa, Saitama, Chiba, Tochigi and Gunma prefectures.
The earthquake was the strongest seismic intensity level measured in central Tokyo since the Great East Japan Earthquake in 2011.
No major damage has been reported, although there have been some disruptions in public transport systems.
The secretariat of the Nuclear Regulation Authority said the quake caused no trouble at nuclear plant facilities in Ibaraki, Niigata and Fukushima prefectures.