Japanese media reported that a Japanese destroyer entered China's territorial water near Taiwan without informing Beijing. This sparked "serious concern" from Beijing.

Kyodo News Agency, citing diplomatic sources, reported that the destroyer Suzutsuki of Japan's Maritime Self-Defense Force sailed in China's waters near Zhejiang Province on July 4 where China had declared it would conduct drills.

NTV, citing sources from Japan's Defence Ministry, reported that Suzutsuki was tasked with monitoring Chinese missile exercises north of Taiwan in the East China Sea. He entered the waters before notifying China.

Kyodo reported that the destroyer had sailed for 20 minutes within 12 nautical mile (22 km) of Zhejiang's coast despite warnings from Chinese vessels. Beijing then expressed "serious concern" to Tokyo.

Kyodo reported that the Japanese defence ministry launched an investigation into the captain's conduct and crew's intentions.

China's coastguard and naval vessels entered Japan's waters. In June of last year, Tokyo protested against Beijing for the Chinese navy sailing into Japanese waters near Yakushima Island.

The Chinese military claimed that a U.S. Navy vessel "illegally entered" waters near a disputed South China Sea island. This atoll has been the scene of several maritime clashes, including with the Philippines. (Reporting and editing by Michael Perry; Kantaro Kommiya)