An earthquake measuring 6.2 on the Richter scale on Sunday rocked Fukushima Prefecture and its vicinity in Honshu Island of Japan, said the Japan Meteorological Agency.
The focus of the quake, which occurred at 12:33 a.m. local time (0333 GMT), was located some 40 km under the sea of Fukushima in northeastern Honshu, said the agency.
There were no immediate reports of casualties or damage to properties, and no tsunami warning was issued.
There was no damage to nuclear plants in Fukushima, according to Tokyo Electric corporation, and the nearby Sendai Airport's operation has not been affected.
The quake registered lower 5 on the Japanese seismic intensity scale of 7 in part of Fukushima and 4 in some other parts of the prefecture and Miyagi, Yamagata, Ibaraki, and Tochigi prefectures.
It was also felt in Tokyo metropolitan area, some 200 km south of Fukushima.
The U.S. Geological Survey (USGS) originally said it was a 6.4- magnitude quake and later revised it down to 6.1 and put it at a shallow 7.7 km depth.