An earthquake with a preliminary magnitude of 6.4 has hit southern Japan, the Japan Meteorological Agency says.
The epicentre of the earthquake was the Bungo Channel, a strait separating the Japanese islands of Kyushu and Shikoku, the agency said, adding that no tsunami warning had been issued.
Ehime and Kochi prefectures were hit by the quake with an intensity of 6 on Japan's 1-7 scale, the JMA said.
No major damage has been reported so far, according to local media reports.
The Ikata nuclear plant in Ehime prefecture, where one reactor is in operation, reported no irregularities, operator Shikoku Electric Power said, according to public broadcaster NHK.
Earthquakes are common in Japan, one of the world's most seismically active areas.
Japan accounts for about one-fifth of the world's earthquakes of magnitude 6 or greater.
On March 11, 2011, the northeast coast was struck by a magnitude 9 earthquake, the strongest quake in Japan on record, and a massive tsunami.
Those events triggered the world's worst nuclear crisis since Chernobyl a quarter of a century earlier.
Australian Associated Press
