An earthquake with a preliminary magnitude of 4.7 shook Ehime Prefecture in southwestern Japan, the Japan Meteorological Agency said.

The quake occurred at 5:53 p.m. and originated in southern parts of Ehime at a depth of around 40 kilometers. It registered 4 on the Japanese seismic intensity scale of 7 in Seiyo city in the prefecture. No tsunami warning was issued, according to Kyodo News Agency on Friday.

Shikoku Electric Power Co. said it has not detected any problems at its three-reactor Ikata nuclear power plant in Ehime Prefecture.