An official Taiwanese news agency says the island has mistakenly fired a supersonic anti-ship missile but there were no injuries caused by the mishap.

The Central News Agency said the 500-ton patrol boat Chinchiang was undergoing an inspection inside a military base when the missile — a Hsiung Feng III — was fired off by accident on Friday.

It says the missile landed in waters off the islands of Penghu near Taiwan and that a preliminary investigation showed that its operators may have failed to follow proper procedures.

The agency says a full investigation is under way.