A Taiwanese warship mistakenly launched a supersonic “aircraft carrier killer” missile towards China on Friday (Jul 1), hitting a fishing boat and killing one person, the navy said, as ties between the island and its once bitter rival deteriorate.

The domestically developed Hsiung-feng III (Brave Wind) missile flew about 75 kilometres before hitting the trawler in waters off Penghu, a Taiwanese-administered island group in the Taiwan Strait.

Later on Friday, Taiwan’s navy clarified that an unsupervised sergeant had pressed the wrong button during a drill.

The skipper on the “Hsian Li Sheng”, a 60-tonne trawler based in the southern Kaohsiuing city, was killed and three other crew on board, including a Vietnamese and a Filipino, were injured.

“An initial investigation showed that the incident has caused the death of the skipper,” Taiwan’s defence ministry spokesman Chen Chung-chi told reporters. “We apologise to the family of the skipper and would like to convey our condolences to them.”

The missile was fired during a drill at around 8.10 am (0010 GMT) from a 500-tonne missile ship docked at a naval base in the southern city of Tsoying and flew in the direction of China.

The navy said the missile went through the trawler, but did not explode, nor did it sink the fishing vessel.

It added that it was not immediately clear how the missile, which has a range of 300 kilometres, had come to be launched, but suggested it could have been due to human error.

“Our initial investigation found that the operation was not done in accordance with normal procedure,” Vice Admiral Mei Chia-shu told reporters, adding that an investigation was under way.