TOKYO -- A 7.1-magnitude earthquake struck Miyazaki Prefecture and other areas in southwestern Japan on Thursday, the country's weather agency said.

Tsunami advisories have been issued for Miyazaki, Kochi, Ehime, Oita, Kagoshima prefectures on the islands of Kyushu and Shikoku, according to the Japan Meteorological Agency (JMA).

Miyazaki Port in the southern Miyazaki Prefecture was hit by 50 cm tsunami waves following the quake, the JMA said.

No abnormalities were found in nuclear plants near the quake-hit area, Kyodo News reported.

Kyushu Shinkansen bullet train service was halted after the quake, the report added.

The earthquake, measuring lower 6 on the Japanese seismic intensity scale of 7, occurred at 16:43 local time. At a depth of 30 km, the epicenter was located off the waters of Hyuga-nada in southern Kyushu, according to the weather agency.

The magnitude had been revised to 7.1 from 6.9.