THE BRP SIERRA MADRE, a marooned transport ship which Philippine Marines live in as a military outpost, is pictured in the disputed Second Thomas Shoal, part of the Spratly Islands in the South China Sea. 鈥 REUTERS

THE CHINESE聽Coast Guard again tried to block a mission by four Philippine ships to resupply troops at a disputed South China Sea atoll on Oct. 4, according to Philippine authorities.

In a statement, the National Task Force for the West Philippine Sea said several Chinese coast guard and maritime militia vessels had tried to 鈥渂lock, harass, and interfere鈥 with the Philippines鈥 routine rotation and resupply mission to BRP Sierra Madre, a World War II-era vessel that was intentionally grounded at Second Thomas Shoal in 1999 to assert Manila鈥檚 claims.

Unaizah May 1 and Unaizah May 2 were escorted by Philippine Coast Guard vessels BRP Cabra and BRP Sindangan during the successful resupply mission, which was conducted 鈥渦pon instructions of President Ferdinand R. Marcos, Jr.鈥

鈥淒espite attempts by a significant number of China Coast Guard and Chinese Maritime Militia vessels to block, harass and interfere with the routine mission, Philippine supply ships鈥 successfully reached BRP Sierra Madre,鈥 the task force said.

China condemned the mission, saying the vessels had entered its waters in the Spratly Islands without its consent.

While China is in dispute with several of its neighbors over its extensive claims in the South China Sea, its relations with the Philippines have been particularly fraught recently over the issue, especially since Ferdinand R. Marcos, Jr. took over as Philippine president last year.

鈥淧hilippine supply ships and two coast guard ships entered the waters… in China鈥檚 Nansha Islands without permission from the Chinese government,鈥 China Coast Guard spokesman Gan Yu said a post on its website, using China鈥檚 name for the Spratly Islands.

The atoll in the area is known as Ayungin in the Philippines, while China calls it Renai Reef. Also known as the Second Thomas Shoal, it is 105 miles (109 kilometers) off the Philippine island of Palawan.

A small number of Philippine troops live on board the old navy transport ship, the BRP Sierra Madre, which the Philippines grounded at the shoal in 1999 to reinforce its sovereignty claim.

China Coast Guard said in its post it had issued stern warnings to the Philippine boats, adding that BRP Sierra Madre 鈥渟its on the beach鈥 illegally.

Raymond Powell, a fellow at the Gordian Knot Center for National Security Innovation, said at least 12 Chinese militia ships were deployed to block the Philippine resupply mission.

Two Chinese militia ships passed within a few meters of the Philippine Coast Guards two Parola-class vessels, he tweeted. Two other Chinese Coast Guard vessels 鈥渞emained AIS-dark but were likely in the area and involved.鈥

AIS or automatic identification system 鈥渢ransmits a ship鈥檚 position so that other ships are aware of its position,鈥 according to the Global Fishing Watch.

鈥楲EGITIMATE EXERCISE鈥
The task force said resupply missions are 鈥渁 legitimate exercise of the administrative functions of the Philippine government over the West Philippine Sea,鈥 which refers to areas in the South China Sea within the country鈥檚 exclusive economic zone.

Geopolitical analysts have said BRP Sierra Madre, which was donated by the US to the Philippine government in 1997, has been crucial in preserving the status quo in the South China Sea, with China fearing an activation of a 1950s Mutual Defense Treaty between Manila and Washington once it attacks a Philippine vessel.

Speaker Ferdinand Martin G. Romualdez in a statement said the House of Representatives would allot funds to build critical infrastructure on Thitu Island including storm shelters for fishermen, a solar power plant and cold storage facilities.

鈥淚t鈥檚 clear that Pag-asa Island needs a development plan,鈥 he said, referring to Thitu. 鈥淭he House of Representatives will take the lead in coming up with such plan, being the institution responsible for the national budget and national policies that need legislation.鈥

The Philippines last completed a resupply mission to the grounded ship on Sept. 8. A month earlier, a China Coast Guard vessel fired water cannons at a Philippine supply boat during a similar attempt, drawing condemnation from the Philippines and old ally the United States.

China has told the Philippines to tow the vessel away, but Manila has rejected the demand.

The Philippine National Security Council (NSC) said its resupply and rotation mission was completed despite attempts by a significant number of China Coast Guard and Chinese maritime militia to 鈥渉arass and interfere鈥 with it.

鈥淭hese missions are a legitimate exercise of the administrative functions of the Philippine government,鈥 the council said.

China claims sovereignty over almost the entire South China Sea, pointing to a line on its maps that cuts into the exclusive economic zones of Vietnam, the Philippines, Malaysia, Brunei and Indonesia.

The United Nations-backed Permanent Court of Arbitration in The Hague in 2016 said the line on China鈥檚 maps had no legal basis. 鈥 Kyle Aristophere T. Atienza with Reuters