China employed what appeared to be a new tactic during its latest clash with the Philippines in the flash point South China Sea, with Manila claiming Chinese vessels had engaged in “dangerous maneuvers,” including attempting to tow one of its ships.

Chinese and Philippine vessels have repeatedly clashed in the South China Sea, particularly near Second Thomas Shoal, a submerged reef claimed by both sides, but controlled by Manila. Vessels from both sides have collided during these clashes numerous times, but any attempt by the Chinese to tow away a Philippine ship could be seen as an escalation on the part of Beijing.

Washington, which has a mutual defense pact with Manila, condemned the “escalatory and irresponsible actions” by China to prevent the Philippines from “lawfully delivering humanitarian supplies” to service members stationed at a Philippine garrison built on a rusting hulk of the BRP Sierra Madre, a warship purposefully grounded on the shoal in 1999.