Tsunami alert as powerful quake hits western Japan

It issued a tsunami advisory, predicting waves of up to one metre along the southern coast of Kyushu and nearby island of Shikoku.

Operators of nuclear plants on Kyushu and Shikoku said they were checking to see if there was any damage to them.

Japan's NHK public television said there were reports of broken windows at the Miyazaki airport near the epicentre.

Japan sits on the Pacific "Ring of Fire", the line of seismic faults encircling the Pacific Ocean, and is one of the world's most earthquake-prone countries.

An earthquake on January 1 in Japan's north-central region of Noto left more than 240 people dead.