TOKYO: A powerful earthquake struck off Japan's southern coast on Thursday, triggering a tsunami advisory.

The Japan Meteorological Agency said the quake registered magnitude 7.1 and was centred off the eastern coast of Japan's southern main island of Kyushu at a depth of about 30 km (18.6 miles).

It issued a tsunami advisory, predicting waves of up to 1 metre (3.3 feet) 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 Jan 1 in Japan's north-central region of Noto left more than 240 people dead.