Manila summoned Beijing's ambassador and China lodged a complaint on Monday in a growing spat over two collisions between Philippine and Chinese vessels in the disputed South China Sea.
The countries have traded blame over Sunday's incidents near Second Thomas Shoal in the Spratly Islands, with both sides filing diplomatic protests and releasing videos to support their accusations.
The two collisions happened during a routine Philippine resupply mission to Filipino troops stationed on a navy vessel that was grounded on the shoal to assert Manila's territorial claims.
"We're making full use of diplomatic processes... available to us. That includes summoning the Chinese ambassador (Huang Xilian), which we did this morning," Philippine foreign ministry spokesperson Teresita Daza told reporters.
Daza said the ambassador was unavailable and was represented by his deputy chief of mission during the meeting.
Huang was last summoned to the foreign ministry in August after the China Coast Guard used water cannon on Philippine vessels near Second Thomas Shoal.
"Ayungin Shoal is part of our exclusive economic zone and continental shelf and we have sovereign rights and jurisdiction over it," Daza said, using the Philippine name for the shoal.
A Chinese diplomat made "solemn representations... expressing strong dissatisfaction and resolute opposition to the trespassing" by Philippine vessels into the Ren'ai Reef area, China's embassy in Manila said, using China's name for the shoal.
The Philippines has accused a China Coast Guard vessel of "reckless manoeuvres" that led to a collision with a smaller wooden boat contracted by the Armed Forces of the Philippines to deliver provisions to troops on the BRP Sierra Madre.
China said the "slight collision" happened after the resupply boat ignored "multiple warnings and deliberately passed through law enforcement in an unprofessional and dangerous manner", state broadcaster CCTV reported Sunday, citing the foreign ministry.
In another incident, a Philippine coastguard vessel escorting the resupply mission was "bumped" by what Manila has described as a "Chinese Maritime Militia vessel".
China, however, accused the Philippine boat of "deliberately" stirring up trouble by reversing in a "premeditated manner" into a Chinese fishing vessel.
'Arbitral ruling is binding'
China claims almost the entire South China Sea, through which trillions of dollars in trade passes annually, and has ignored a 2016 international ruling that its assertion has no legal basis.
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.
As China moves ever more confidently to assert its claims to the waters, officials and experts have warned of the potential for collisions.
Despite the challenges, the Philippines would "continue to do what is necessary" to supply its troops at Second Thomas Shoal with provisions, said Jonathan Malaya, assistant director general of the National Security Council.
"This is the Philippines implementing the 2016 arbitral ruling," Malaya told reporters Monday.
"The arbitral ruling is binding not only to the Philippines but also to China."
The Philippine Navy deliberately grounded the World War II-era BRP Sierra Madre on Second Thomas Shoal in 1999 to check China's advance in the waters.
The troops stationed on the crumbling ship depend on regular supply deliveries.
The Philippines has outposts on nine reefs and islands in the Spratlys, including Second Thomas Shoal.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
