The Philippines has condemned China’s coast guard activity in the South China Sea.

MANILA – The Philippines criticised “in the strongest terms” the conduct of three Chinese Coast Guard vessels that halted and fired water cannons on two Manila supply boats on their approach to a Philippine-occupied atoll in the South China Sea, according to the country’s top diplomat on Thursday.

According to Foreign Affairs Secretary Teodoro Locsin, no one was injured during the Nov 16 incident at the Second Thomas Shoal, but the Philippines boats, which were bringing food supplies to military soldiers stationed there, had to abandon their mission.

“The Chinese Coast Guard’s actions are unlawful,” Locsin said in a statement, reminding China that the Philippines-United States Mutual Defense Treaty covers public vessels.

Locsin stated that he had expressed “our shock, disapproval, and protest of the act” to the Chinese Ambassador in Manila “in the harshest terms.”

Locsin cautioned that Beijing’s “failure to exercise self-control endangers the unique relationship” between the two countries.

“In and around these territories, China has no law enforcement authority. They must pay attention and back off “Locsin said.

Second Thomas Shoal, located 105 nautical miles (195 kilometres) southwest of the Philippine province of Palawan, is considered to be within Manila’s 200-nautical-mile exclusive economic zone. It has been occupying the shoal since 1999, when it deliberately grounded a naval ship on the reef.

China, which claims almost the entire South China Sea, claims the reef as part of its territory, but a 2016 judgement by the Permanent Court of Arbitration in The Hague ruled in favour of the Philippines.

The Chinese embassy in Manila did not immediately react to media demands for comment.

China claims sovereignty over large swaths of the South China Sea, although Brunei, Malaysia, the Philippines, Taiwan, and Vietnam have also made rival claims to parts or all of the islands.