The Japan Meteorological Agency reported that the quake was felt in the municipalities of Ainan, Ehime prefecture, and Sukumo, Kochi prefecture, both on the island of Shikoku.
According to the governments of those territories and local fire departments, six people in Ehime Prefecture and one person in Kochi Prefecture suffered minor injuries, while two were injured in Oita, in the Kyushu region of southwestern Japan.
Services on some train lines were canceled as of Thursday morning.
Separately, a valve defect reduced power output by two percent at the No. 3 reactor at the Ikata nuclear complex in Ehime Prefecture, although no major problems with overall operations were reported.
In Sukumo, 23 people were temporarily evacuated, while water supplies in the city were disrupted due to burst pipes in many places.
Ten residents of Yusuhara, Kochi Prefecture, were also temporarily cut off due to falling trees.
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