Taiwan's navy mistakenly launched a supersonic anti-ship missile from a naval base, killing one person and injuring three, officials say.
A patrol boat was undergoing a drill inspection in Kaohsiung when the Hsiung Feng III missile was set off, Taiwan's Central News Agency (CNA) reported.
It was fired in the direction of mainland China, and hit a fishing boat off the Penghu islands, it added.
The boat's captain, who is Taiwanese, has been killed, defense officials say.
The missile has a range of about 300km (200 miles).
Hundreds of missiles
The incident comes as China celebrates the 95th anniversary of the formation of the Chinese Communist Party.
When asked by reporters if the incident would affect relations with Beijing, Vice-Admiral Mei Chia-hsu said the navy had reported it to the island's defense ministry.
She said the case was under investigation and would be handled "accordingly". It was unclear whether Beijing had been notified directly.
China considers Taiwan a breakaway province, to be reunited with the mainland, by force if necessary.
It has hundreds of missile pointed towards the island at all times.
Taiwanese President Tsai Ing-wen, who is also head of the military, is currently overseas.