Taiwan’s navy on Friday mistakenly fired a supersonic anti-ship missile, although there were no injuries caused by the mishap, the official Central News Agency reported.

The 500-ton patrol boat Chinchiang was undergoing an inspection inside a military base when the missile — a Hsiung Feng III — was fired off and landed about 40 nautical miles (46 miles) away in waters off the islands of Penghu near Taiwan, the agency said.

The French news agency AFP said Taiwanese naval officials had confirmed the splash-down off the Penghu islands, which sit between Taiwan and China.

AFP quoted Vice Admiral Mei Chia-shu as saying the Navy‘s “initial investigation found that the operation was not done in accordance with normal procedure.”