Philippine Marines aboard the BRP Sierra Madre, a dilapidated Philippine Navy ship that has been aground since 1999 and has became a Philippine military detachment on the disputed Second Thomas Shoal, part of the Spratly Islands, in the South China Sea, March 29, 2014.

The Philippines successfully delivered supplies to its troops at a military outpost in the South China Sea despite attempts by Chinese vessels to block its ships from the disputed waters, officials said Tuesday.

Manila carried out the mission two weeks after the China Coast Guard fired water cannons at a Philippine coast guard ship that was escorting a convoy of boats bringing supplies to marines stationed aboard a rusty old navy ship in Ayungin Shoal (Second Thomas Shoal).

The mission on Tuesday “was able to deliver fresh provisions to our military personnel stationed on board BRP Sierra Madre,” the National Task Force for the West Philippine Sea said in a statement.

Manila calls waters of the South China Sea that lie within its exclusive economic zone the West Philippine Sea. The Philippines deliberately ran the World War II era Sierra Madre aground to serve as its outpost there.

The mission was completed “notwithstanding attempts by China Coast Guard (CCG) and Chinese Maritime Militia (CMM) vessels to block, harass, and interfere with the supply mission,” the task force said, adding that Philippine Navy vessels were “on standby during the mission.”

Ahead of the Philippine mission, China deployed at least 11 militia ships to Ayungin Shoal starting Monday, according to Ray Powell, a retired U.S. Air Force colonel who is now a private security analyst focusing on the South China Sea.

“[The] extent of dangerous [People’s Republic of China] maneuvers is hard to assess due to China Coast Guard ships running AIS-dark,” he said on X, the social media site formerly known as Twitter. He was referring to the ships turning off their Automatic Identification System that displays their position.

Code of conduct

As of Tuesday evening, the Chinese Embassy in Manila had not issued a statement.

But Chinese Communist Party newspaper China Daily quoted a China Coast Guard spokesman as saying that the agency had made “temporary special arrangements” allowing the Philippines to carry out the supply mission because its ships were not carrying building materials.

Earlier this month, Chinese media reports quoted the coast guard as confirming it had fired water cannons and alleging that the Philippine supply boats were transporting “illegal building materials.”

Back then Manila “strongly condemned” what it called China Coast Guard illegal actions, saying they disregarded the safety of Filipino sailors and violated international law.

The Philippines in 2016 won a landmark ruling in the Permanent Court of Arbitration in The Hague, which threw out China’s expansive claims in the South China Sea.

Beijing, however, has ignored the ruling and carried on with its military expansionism in the strategic waterway, including building artificial islands.

China claims nearly the entire South China Sea, including waters within the exclusive economic zones of Brunei, Malaysia, the Philippines, Vietnam and Taiwan.

Meanwhile, Philippine Foreign Secretary Enrique Manalo has been trying to engage with China diplomatically to calm tensions.

On Tuesday, the Philippines hosted diplomats from China and other South China Sea claimant nations for another round of negotiations for a “code of conduct” that seeks to prevent conflict in the disputed maritime region.

It was the third meeting on the code this year, with the first two having been held in Indonesia in March and Vietnam in May.

“We are negotiating a Code of Conduct precisely because we would like to prevent incidents such as the last one at the Ayungin Shoal from happening,” foreign affairs spokesperson Ma. Teresita Daza said.

The Philippines, she said, remains committed to an “early conclusion of an effective and substantive” code of conduct.

Soldiers participate in a combat exercise as a part of the Indo-Pacific Endeavor 2023 between the Armed Forces of the Philippines and the Australian Defense Force in Tarampitao Airfield in Rizal, Palawan, Philippines, Aug. 21, 2023. [Jam Sta Rosa/AFP]

Separately, U.S., Australian and Filipino troops held an air assault drill on Monday in Rizal town, in the western island province of Palawan, about 108 nautical miles from Ayungin Shoal.

The exercise, held at Punta Baja Airfield, involved Australia’s helicopter landing dock the HMAS Canberra; frigate HMAS Anzac and multi-role F-35A Lightning II aircraft; U.S. MV-22B Osprey aircraft; and hundreds of troops from the three armed forces.

Exercise Alon 2023 is the first amphibious exercise between Filipino and Australian troops, officials said. It opened in Darwin, Australia on Aug. 14 and will run until Aug. 31.

The exercise involved 700 Filipino and 1,200 Australian troops. About 150 troops from the United Marines Corps are participating but are playing a “support” role only, officials said.

The drills were part of Australia’s Indo-Pacific Endeavor (IPE) for this year. The IPE seeks to strengthen Canberra’s engagement and partnerships in Southeast Asia and the Indian Ocean.

An amphibious landing and live-fire exercises are scheduled to be held in the northern Philippine provinces of Zambales and Tarlac, respectively, in the next few days.

“The scenario is assault from a ship, from sea towards land,” said Armed Forces chief Gen. Romeo Brawner Jr.

“It’s not directed at China,” said Brawner, adding that the three armed forces are honing their skills in Rizal.

He added, though, that Manila had a “right and obligation to bring supplies to our soldiers” anywhere in Philippine territories.

Still, Filipino troops had been directed to strictly observe rules of engagement, Brawner said on Monday.

“We are going to avoid them to prevent an escalation of the situation,” he said.

“We are not going to engage them in a water cannon battle.”

Gerard Carreon and Noel Celis in Manila contributed to this report.