An earthquake measuring 5.9 on the Richter scale on Saturday jolted Japan's Kanto region (eastern Honshu), said the Japan Meteorological Agency.
The quake occurred at 11:19 a.m. (0219 GMT) and was strongly felt in Tokyo and neighboring regions.
The epicenter, with a depth of some 70 kilometers, was determined in the southern part of Tochigi Prefecture.
There were no immediate reports of casualties or damage to properties, and no tsunami warning was issued.
Shinkansen bullet train services were suspended between Tokyo and the Tohoku region (northeastern Honshu) but resumed later.