The Philippines and China clashed in the disputed waters of the South China Sea on Sunday over what Manila said was a fishermen supply mission, the latest in a series of naval and air confrontations in the strategic waterway.

The incident overshadows efforts by both countries to restore trust and better manage disputes after months of confrontations, which included a violent clash in June in which a Filipino sailor lost a finger.

The Philippines on Sunday accused China of “aggressive and dangerous maneuvers” to block the resupply mission. The Chinese coast guard, meanwhile, said it had taken “control measures” against a ship that had “illegally” entered the waters and repeatedly approached Chinese vessels in a dangerous manner.

In the incident near Sabina Reef, Chinese vessels said they rammed and attacked with water cannon a Philippine Fisheries Department vessel carrying food, fuel and medical supplies for Filipino fishermen, the Philippine South China Sea Task Force said.

The Chinese coast guard said the Philippine vessel “ignored repeated serious warnings and deliberately approached and rammed the Chinese police boat,” resulting in a collision. It added that responsibility for the collision lies entirely with the Philippine side.

China claims sovereignty over almost the entire South China Sea, including areas claimed by the Philippines, Taiwan, Malaysia, Indonesia, Vietnam and Brunei. Beijing has deployed a fleet of ships to protect its claims.

An international arbitration tribunal ruled in 2016 that Beijing’s lawsuit had no basis in international law, a landmark victory for the Philippines, which filed the lawsuit. Beijing rejects that decision.

The Philippines and China agreed to “restore trust” and “rebuild” to resolve maritime disputes at a high-level meeting last month, followed by a tentative agreement on Manila’s resupply missions to a stranded Philippine warship in the South China Sea.

“These unprofessional, aggressive and illegal actions posed a serious risk to the safety of the Filipino crew and the fishermen they were meant to serve,” the Philippine task force said of Sunday’s confrontation.

It said the Bureau of Fisheries vessel, operating between Half-Moon Shoal and Sabina Shoal, encountered several Chinese vessels conducting “dangerous maneuvers,” causing its engine to fail and forcing it to abort the resupply mission.

Manila reiterated its call to Beijing to “stop provocative actions that endanger regional peace and security.”

Treaty ally the United States reiterated its support for the Philippines on Sunday.

“Unsafe, unlawful and aggressive behavior by the PRC (People’s Republic of China) has disrupted a legitimate Philippine mission and put lives at risk,” U.S. Ambassador to the Philippines MaryKay Carlson said on the social media platform X.

On Saturday, Manila accused Beijing of “unjustifiably” launching flares from the Chinese-occupied Subi Reef on Thursday while a Manila-based aircraft was conducting patrols.

The Philippines said the same aircraft was “harassed” by a Chinese fighter jet during a surveillance flight near Scarborough Reef on Monday.

(Reuters – Reporting by Karen Lema in Manila and Antoni Slodkowski in Beijing; Editing by Kim Coghill, William Mallard and David Goodman)