China’s military said on Wednesday it monitored and “drove away” a US destroyer that sailed near the disputed Scarborough Shoal in the strategic busy waterway of the South China Sea.

Axar.az reports, citing Reuters, the first known US military operation in at least six years within the shoal’s waters came a day after the Philippines accused Chinese vessels of “dangerous maneuvers and unlawful interference” during a supply mission around the atoll.

In a statement, the Chinese military’s Southern Theatre Command said the USS Higgins had entered the waters “without approval of the Chinese government” on Wednesday.

“The US move seriously violated China’s sovereignty and security, severely undermined peace and stability in the South China Sea,” it added, vowing to keep a “high alert at all times”.

China claims almost the entire South China Sea, despite overlapping claims by Brunei, Indonesia, Malaysia, the Philippines, Taiwan and Vietnam.

The United States regularly carries out “freedom of navigation” operations in the South China Sea, challenging what it says are curbs on passage imposed by China and other claimants.