Magnitude 6.9 earthquake hits southwestern Japan

A 20cm tsunami was later recorded reaching Miyazaki city, public broadcaster NHK reported. 

The city - the prefectural capital - has a population of roughly 400,000 people.

There were no abnormalities reported at the Ikata Nuclear Power Plant in western Japan or the Sendai Nuclear Power Plant in Kagoshima prefecture, NHK said, referring to the two plants nearest to where the quake occurred.

The JMA is investigating whether the quake was related to the Nankai Trough, NHK said.

Japan in August issued its first-ever advisory of higher-than-usual risks of a megaquake after a strong quake occurred at the edge of a tremulous seabed zone along the Pacific coast known as the Nankai Trough.