Image copyright Getty Images Image caption The incident happened as civilian and military vessels were conducting joint search and rescue drills
China’s Coast Guard has fired water cannons on Philippine military and civilian supply vessels, the Philippines says.
The incident happened as the military was conducting joint search and rescue drills near their disputed South China Sea islands.
The vessels were patrolling for Vietnamese fishing boats that had lost contact with their capsized vessel, the Philippine military said.
China claims almost the entire sea, where about $5tn (£3.8tn) in annual trade passes through.
“A supply boat collided with the Chinese coast guard,” defence spokesman Brigadier General Restituto Padilla said.
“The Chinese coast guard responded using water cannons and the vessel had to retreat,” he added.
The force was investigating the incident, General Padilla said.
“Our military is conducting joint drills… They were searching for Vietnamese boat… as we catch them we call the Vietnamese Coast Guard and ask for help.”
This is the latest of a series of incidents between the two sides this year, amid tension around the South China Sea.
On Thursday, Vietnamese state media said that China had landed surveillance planes on the Paracel Islands, home to the largest of its disputed islets.
Two Chinese ships have also been arrested and charged with illegally fishing in the South China Sea, according to Vietnam’s maritime agency.