The Philippines says the China Coast Guard has fired water cannon and “sideswiped” a government vessel in the South China Sea.
The incident happened near the disputed Scarborough Shoal and Beijing said it acted “in accordance with the law”.
The US ambassador to the Philippines condemned China’s “unlawful use of water cannons and dangerous manoeuvres”.
The South China Sea is at the centre of a territorial dispute between China, the Philippines and other countries. But tensions between Manila and Beijing have sharply escalated in the last year.
On Wednesday, Manila released a video appearing to show a Chinese coast guard ship blasting water at a Philippines fisheries department vessel.
Separate footage, apparently taken from the Philippine ship, showed its crew shouting “Collision! Collision!” as the Chinese boat crashes into it.
The BBC has not independently verified the footage.
The Philippine coast guard said the Chinese coast guard ship “intentionally sideswiped” the ship and then “launched a second water cannon attack on the same vessel”.
China’s coast guard said in an initial statement that Philippine ships “came dangerously close” and that its crew’s actions had been “in accordance with the law”.
It later accused the Philippines of making “bogus accusations in an attempt to mislead international understanding” and said it had deliberately collided with the Chinese ship.
But MaryKay Carlson, US ambassador to the Philippines, said “we condemn these actions” by China.
In a post on X, she said that “unlawful use of water cannons and dangerous manoeuvres disrupted a Philippine maritime operation … putting lives at risk”.
This is the latest in a string of dangerous encounters in the last year as the two sides seek to enforce their claims on disputed reefs and outcrops in the South China Sea, including the Second Thomas Shoal and the Scarborough Shoal.
The collisions usually arise from the cat-and-mouse games the boats engage in, as they attempt to chase the other side away.
China has increasingly blasted powerful water cannon and lasers at Philippine ships, with the Filipinos also accusing the Chinese of boarding their boats, leading to scuffles, as well as confiscating items and puncturing their inflatable vessels.
