A fresh maritime clash erupted in the South China Sea on Saturday as China's coast guard used water cannons against Philippine boats attempting to resupply troops stationed on a contested shoal. The incident, which caused significant damage to a civilian vessel and injured personnel, has escalated tensions between the two nations just days after the United States reaffirmed its commitment to defending Philippine access to the disputed waterway.

According to the Armed Forces of the Philippines (AFP), a Philippine civilian boat suffered "heavy damage" from the water cannon attack, which occurred in the vicinity of the Second Thomas Shoal, also known as Ayungin Shoal by the Philippines and Ren'ai Reef by China. The AFP accused the Chinese coast guard of performing a "dangerous maneuver" by crossing the bow of the resupply vessel before deploying the water cannon and subsequently installing floating barriers to prevent further entry of any vessels.

The Philippine Coast Guard reported that one of its vessels had been "impeded and encircled" by a Chinese coast guard ship and two Chinese "maritime militia" vessels, effectively isolating it from the resupply boat. Jay Tarriela, a spokesperson for the Philippine Coast Guard, stated that the Chinese maritime forces had shown "a disregard for the Convention on the International Regulations for Preventing Collisions at Sea" through their "irresponsible and provocative behavior."

The Second Thomas Shoal, located approximately 200 kilometers (125 miles) from the coast of the Philippine island of Palawan, has long been a point of contention between Beijing and Manila. In the 1990s, the Philippines grounded an aging World War II-era navy transport ship, the BRP Sierra Madre, on the shoal to help enforce its claim to the area. The mostly rusted wreckage is now manned by Philippine marines stationed on rotation, and recent clashes have occurred when the Philippines attempts to resupply these forces.

Despite the incident, the AFP confirmed that it had successfully resupplied the Sierra Madre, although one of the vessels involved in the operation could not continue its course. In a post on Chinese social media platform Weibo, China's coast guard claimed to have taken "control measures in accordance with the law" against the Philippine ships, which it accused of having "illegally entered the waters adjacent to Ren'ai Reef."

The clash comes on the heels of U.S. Secretary of State Antony Blinken's visit to Manila earlier this week, during which he reiterated Washington's "ironclad commitment" to defending the Philippines in the South China Sea. Speaking at a joint news conference with his Philippine counterpart, Blinken emphasized the allies' "shared concern about the PRC's (People's Republic of China) actions that threaten our common vision for a free, open Indo-Pacific, including in the South China Sea and in the Philippines' exclusive economic zone."

Blinken also reaffirmed that the mutual defense treaty signed between the two countries in 1951, which obligates the United States to defend Manila from attack, extends to "armed attacks on the Filipino armed forces, public vessels, aircraft - including those of its coast guard - anywhere in the South China Sea."

China claims almost the entire South China Sea, including the Second Thomas Shoal, which falls within the Philippines' 200-mile exclusive economic zone. A 2016 ruling by the Permanent Court of Arbitration found that China's sweeping claims have no legal basis. However, Beijing has continued to deploy vessels to patrol the disputed atoll, leading to increased tensions with its neighbors in recent years.

The Philippine task force on the South China Sea released a statement condemning China's actions as "irresponsible and provocative," while emphasizing that the Philippines will not be deterred "by veiled threats or hostility" from exercising its legal rights over its maritime zones, including the Second Thomas Shoal. China's foreign ministry, on the other hand, warned that "if the Philippines continues to act unilaterally, China will continue to take resolute measures to safeguard its territorial sovereignty and maritime rights and interests."