(Bloomberg) -- Chinese and Philippine vessels faced off in multiple clashes in the South China Sea over the weekend as tensions continued to escalate between the two countries over maritime territory, prompting the US to reiterate its commitment to defend Manila.

The Philippines’ sea task force said its vessels were damaged after being “directly targeted” on Sunday by a Chinese coast guard ship with a water cannon during a supply mission to Second Thomas Shoal. A Filipino boat was also rammed by a Chinese vessel, the task force said in a statement.

China’s coast guard said the Philippine boat ignored warnings and “deliberately collided” with its vessel, which was sailing normally for law enforcement purposes. The responsibility lies entirely with the Philippines, the coast guard said in a statement.

“The Philippines should immediately stop its infringements and strictly control frontline provocations,” China Coast Guard spokesman Gan Yu said on Weibo. The Chinese authority will resolutely safeguard national sovereignty and maritime rights, he said.

The actions taken by China’s ships around Second Thomas Shoal and Scarborough Reef “reflect not only reckless disregard for the safety and livelihoods of Filipinos, but also for international law,” the US State Department said in a statement.

“The United States stands with our Philippine allies in the face of these dangerous and unlawful actions,” it added, as it reaffirmed the two nations’ 1951 Mutual Defense Treaty. 

China has laid sweeping claims over the South China Sea, an assertion that’s been met by growing pushback in the Philippines under President Ferdinand Marcos Jr., whose administration has publicized Beijing’s tactics in the disputed waters.

Marcos has slammed China’s “dangerous actions” against Philippine ships, saying they’re an “outright and blatant violation of international law.”

“No one but the Philippines has a legitimate right or legal basis to operate anywhere in the West Philippine Sea,” Marcos said in a post on X late on Sunday, using Manila’s term for the South China Sea.

Philippine armed forces chief Romeo Brawner Jr. who was aboard the resupply boat that was rammed by a Chinese coast guard vessel, said he witnessed the incident himself. “I was furious with what China did and I felt sorry for our troops. They go through this at every resupply mission,” he told reporters.

A group of 200 civilians from the Philippines had set sail to the disputed waters on Sunday and were forced to cut short their trip after they said they were shadowed by four Chinese vessels including two navy ships. The convoy, escorted by the Philippine Coast Guard, had planned to go near Second Thomas Shoal and parts of the Spratly Islands to deliver supplies to fishing communities.

The group of youth leaders, fisherfolk and media personnel decided on “erring on the side of caution” and returning to Palawan province after the “constant shadowing,” its organizer said.

Manila on Saturday reported that the Chinese Coast Guard fired water cannons at Filipino civilian ships near Scarborough Shoal, drawing US condemnation.

The US has pledged to continue bolstering ties with Indo-Pacific allies to counter Beijing’s expansive claims in the crucial waterway. The Philippines has strengthened its longstanding defense alliance with Washington, expanding access for American soldiers and holding joint patrols in contested waters.

--With assistance from Felix Tam, Manolo Serapio Jr., Natalie Choy and Cliff Venzon.

(Updates with details throughout.)

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