Japan has been struck by a 6.1-magnitude earthquake in same region a 7.4 magnitude quake rattle the country just three days ago.

The Japan Meteorological Agency says a magnitude-6.1 earthquake struck Thursday morning off the shore of southern Fukushima prefecture.

It said that there may be slight changes in sea levels, but there is no risk of damage from a tsunami.

No abnormalities were observed at two nuclear power plants near the epicenter off the northeastern Japan coast — the crippled Fukushima No. 1 and idled Fukushima No. 2 — after the 6:23 a.m. quake, Tokyo Electric Power Company Holdings Inc. said.

The earthquake was felt in Tokyo, 225 kilometers (140 miles) southwest of the epicenter.