(Bloomberg) -- Chinese and Philippine ships collided again in the disputed South China Sea on Monday, ratcheting up tensions and prompting the US to condemn Beijing for “irresponsible actions” causing bodily injury.

China’s navy, coast guard and maritime militia vessels engaged in “dangerous maneuvers, including ramming and towing” while Philippine ships conducted a routine resupply mission to its military outpost in Second Thomas Shoal, according to Manila’s task force on the contested sea.

For its part, the China Coast Guard said the Philippine supply ship “deliberately collided” with Chinese vessels and it took “control measures” such as warning and interception, boarding and inspection, and forced eviction against Philippine vessels “in accordance with the law.”

China’s actions “caused bodily injury, damaged Philippine vessels and hindered lawful maritime operations,” US Ambassador to the Philippines MaryKay Carlson said in a post on X. 

The State Department condemned China’s “escalatory and irresponsible actions.” It also reaffirmed that Washington’s 1951 defense treaty with Manila extends to armed attacks on Philippine armed forces and coast guard anywhere in the South China Sea.

Ships from both nations have increasingly clashed in the South China Sea over the past year as Manila, under President Ferdinand Marcos Jr., pushed back against Beijing’s expansive claims over the resource-rich waterway.

Watch: Why the South China Sea Could Spark a War

“China’s dangerous and reckless behavior in the West Philippine Sea shall be resisted by the Armed Forces of the Philippines,” Defense Secretary Gilberto Teodoro said in a statement, using Manila’s name for the waters that’s within its exclusive economic zone.

Amid heightened tensions with China, the Marcos administration has bolstered security ties with the U.S., Japan and other nations.

The Philippines, US, Japan and Canada conducted a maritime cooperative activity on Sunday and Monday in Manila’s exclusive economic zone in a bid to uphold freedom of navigation and reaffirm commitment to bolstering regional security and stability, the U.S. Pacific Fleet said in a statement.

--With assistance from Janine Phakdeetham and Catherine Wong.

(Updates with details throughout.)

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