Tsunami alert as powerful quake hits western Japan

A powerful earthquake has struck off Japan's southern coast, triggering a tsunami advisory.

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

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

No other details were immediately available.