Tokyo: An earthquake of magnitude 6.1 struck off Fukushima early on Thursday, Japan meteorological agency here said. No tsunami warnings were issued.
The epicentre of the shallow quake was in the waters offshore the Fukushima prefecture.
No major damage or injuries were reported.
No abnormalities were observed at the Fukushima nuclear power plants.
Another strong quake of magnitude 7.4 had hit the same area on Tuesday.