A Philippine boat and a Chinese Coast Guard ship collided near a hotly contested reef on Sunday, with both countries trading blame for the latest such confrontation in the disputed South China Sea.
The incident happened during a Philippine resupply mission to a tiny garrison on Second Thomas Shoal in the Spratly Islands, which is a flashpoint for Manila and Beijing.
It comes a day after the Philippines accused the Chinese coast guard of using water cannons to "obstruct" three government boats delivering provisions to Filipino fishermen near Scarborough Shoal, off the main island of Luzon.
Longstanding tensions between Manila and Beijing over the hotly contested sea have flared in recent months following several incidents involving Philippine and Chinese vessels, including two previous collisions.
China claims almost the entire South China Sea.
It deploys boats to patrol the busy waterway and has built artificial islands that it has militarised to reinforce its claim.
The Philippine Coast Guard said a Philippine boat carrying provisions was "rammed" by a Chinese coast guard ship during Sunday's resupply mission.
Jay Tarriela, the coast guard spokesman for the West Philippine Sea, said on social media platform X that a Chinese ship also "water cannoned" three Philippine vessels, causing "serious engine damage" to one of the boats.
The China Coast Guard, however, accused the Philippine boat of "deliberately colliding" with the Chinese vessel after "disregarding our multiple stern warnings".
The Philippine boat "changed direction suddenly in an unprofessional, dangerous manner, deliberately colliding with our Coast Guard Vessel 21556, which was on a normal law enforcement route, and caused a scrape", the China Coast Guard said in a statement.
- Escalating tensions -
Hours before the latest incident, a civilian convoy involving 100 Filipino fishermen embarked on a trip that would pass Second Thomas Shoal as part of a mission to deliver Christmas cheer and provisions to a remote outpost.
Second Thomas Shoal is about 200 kilometres (124 miles) from the western Philippine island of Palawan, and more than 1,000 kilometres from China's nearest major landmass, Hainan island.
A handful of Filipino troops are stationed on the crumbling BRP Sierra Madre, which the Philippine Navy grounded on the reef in 1999 to check China's advance in the waters.
The troops depend on the resupply missions for their survival.
It is not clear if the supply boats were able to deliver their cargo on Sunday.
The Philippines and China have a long history of maritime incidents in the contested South China Sea, through which trillions of dollars of trade pass annually.
Tensions between Manila and Beijing have escalated as China becomes more assertive in pressing its claims to the waters, with the Philippines publishing strongly-worded statements with videos and photos of the incidents.
Philippines President Ferdinand Marcos, who took power in June 2022 and immediately set about improving ties with traditional ally Washington, warned last month that the situation in the South China Sea had become "more dire".