Chinese coast guard vessels fired water cannons and side-swiped a Manila fisheries bureau boat on the way to deliver supplies to Filipino fishermen in the area, according to Philippines officials, a move that drew condemnation from the United States.
The incident follows a diplomatic spat in November after China drew baseline "territorial waters" around the prime fishing patch of the Scarborough Shoal, and submitted nautical charts this week to the United Nations setting out its claim, which Manila said was "baseless" and "illegal."
"This is actually overkill," Philippine Coast Guard (PCG)Spokesperson Jay Tarriela said in a press conference where he shared video clips showing a larger Chinese coast guard ship approaching the smaller fisheries vessel until they collided, and the same Chinese vessel firing a stream of water at the same Manila boat.
China's actions disrupted Philippine maritime operations and put lives at risk, United States Ambassador MaryKay Carlson said on social media platform X, adding that the U.S. stands with likeminded allies in support of a free and open Pacific.
But China's Coast Guard said four Philippine ships had attempted to enter its territorial waters around the Scarborough Shoal, which Beijing claims as Huangyan Island.
Philippine ships had "dangerously approached" the coast guard's "normal law enforcement patrol vessels", prompting them to "exercise control" over their counterparts, Liu Dejun, a coast guard spokesperson, said in a statement.
In a further statement, Liu added that one of the Philippine ships "ignored" repeated warnings, with actions that "seriously threatened" the safety of a Chinese coast guard vessel.
"We warn the Philippines to immediately stop infringement, provocation and propaganda, otherwise it will be responsible for all consequences."
Manila and Beijing have sparred at sea this past year, as Beijing claims almost all of the South China Sea, which has angered neighbouring countries that dispute some boundaries they say cut into their exclusive economic zones.
Tarriela said it was China's Coast Guard "that is provocative and escalating tensions." He also raised concerns over the actions of a Chinese navy vessel on Wednesday which he said shadowed a PCG vessel for the first time in the shoal.
On Monday, China submitted to the United Nations nautical charts showing its territorial claims to the waters around the Scarborough Shoal.
The submission was "a legitimate activity to defend (China's) territorial sovereignty and maritime rights and interests," as a party to the UN Convention on the Law of the Sea (UNCLOS), it said in a statement.
Alexander Lopez, spokesperson for the Philippines' National Maritime Council, maintained "that area is ours" and that China's claims were baseless and illegal.
In the same press conference, Lopez called on China to exercise self-restraint.
"The aggressive posture of the Chinese vessels highlights a continuing pattern of aggression, coercion, and intimidation within Philippine waters," Lopez said.
The Philippines and other members of the Association of Southeast Asian Nations have spent years negotiating a code of conduct with Beijing for the strategic waterway, with some nations in the bloc insisting that it be based on UNCLOS.
China says it backs a code, but does not recognise a 2016 arbitral ruling that its claim to most of the South China Sea had no basis under UNCLOS.
Sovereignty over the Scarborough Shoal has never been established, but the tribunal did rule that China's blockade there violated international law that the area was a traditional fishing ground used by fishermen of many nationalities.
