An earthquake with a magnitude of 5.7 struck north of Tokyo on Sunday evening, local time. There was no tsunami.
The Japan Meteorological Agency says the quake occurred at 7:05 p.m. and registered an intensity of 5 minus on the Japanese seismic scale of zero to 7 in Tokai Village, Ibaraki Prefecture.
An intensity of 4 was registered in some other municipalities in Ibaraki as well as in Fukushima and Tochigi prefectures.
Intensities of 3 to one were logged in wide areas of eastern and central Japan.
The agency says the focus was off the coast of Ibaraki at a depth of 45 kilometers.
It also says the quake is believed to be an aftershock of the 2011 Great East Japan Earthquake.
Agency officials warn that more quakes could occur over the next few days in areas hit by Sunday's jolt.
Professor Furumura Takashi of the University of Tokyo's Earthquake Research Institute says the quake occurred where two tectonic plates meet.
He says the area has been seismically active, with a magnitude-7 quake taking place every dozen years or so. He adds that the impact of the 2011 earthquake is still continuing.
Furumura urges people to keep in mind that the area is prone to strong quakes and to improve their disaster preparedness.