A strong earthquake with a preliminary magnitude of 7.1 hit western Japan on Thursday, affecting the southwestern islands of Kyushu and Shikoku.

Authorities have issued a tsunami warning for multiple regions and are closely monitoring the situation, according to public broadcaster reports.

Initially, NHK reported the earthquake had a preliminary magnitude of 6.9. A tsunami advisory has been issued for the prefectures of Miyazaki, Kochi, Oita, Kagoshima, and Ehime. According to Reuters, citing NHK, 20-centimeter-high waves have already been observed in Miyazaki prefecture on Kyushu.