An earthquake with a preliminary magnitude of 6.2 rocked Tokyo and surrounding areas of eastern Japan on Friday, but there was no threat of a tsunami, the weather agency said.
The quake occurred at 7:03 p.m., registering a lower 5 on the Japanese seismic intensity scale of 7 in parts of Ibaraki and Chiba prefectures, according to the Japan Meteorological Agency.
Bullet trains on the Hokuriku, Joetsu and Tohoku Shinkansen lines were halted for around 10 minutes due to a temporary blackout, East Japan Railway Co. said.
There were no immediate reports of casualties due to the earthquake.
Central Tokyo as well as the neighboring cities of Yokohama and Saitama observed an intensity of 3.
The quake's focus was at a depth of about 50 kilometers off the east coast of Chiba.
No abnormalities were reported at the Tokai No. 2 nuclear power plant located in Ibaraki, northeast of Tokyo, its operator said.
Chiba Prefecture experienced an earthquake with an intensity of upper 5 on May 11.