China Seizes Reef Near Philippine Military Outpost in South China Sea

China has seized control of Sandy Cay, an uninhabited reef near a major Philippine military outpost, escalating tensions in the disputed South China Sea.

Chinese state-run media reported Saturday that China Coast Guard officers landed on Sandy Cay, unfurled the Chinese flag, and conducted what Beijing described as “maritime management and sovereign jurisdiction” activities.

Photographs released showed Chinese officers planting the flag on the reef, known in China as Tiexian Jiao, located just over three kilometers from Thitu Island (Pag-asa Island), home to Philippine military facilities and about 250 residents.

The operation marks one of the most assertive moves by Beijing in the Spratly Islands in recent years, adding to fears of a potential clash in the resource-rich and heavily contested region.

China’s Global Times reported that officers inspected the reef, removed debris such as plastic bottles and wood, and recorded alleged “illegal activities” as part of their landing.

In January, Beijing accused Philippine naval vessels of attempting an “illegal landing and sand sample collection” at Sandy Cay, claiming its forces had “repelled” the effort.

The Philippines has sent its own coast guard ships to monitor the reef, amid concerns that China may be preparing for small-scale reclamation projects similar to its 2013-2016 island-building spree.

China’s claim that Sandy Cay is a natural feature — rather than man-made — could justify a 12-nautical-mile territorial sea under international law, overlapping the waters around Thitu Island.

The strategic significance of Sandy Cay extends beyond its size, potentially strengthening China’s territorial claim over nearby Subi Reef, which hosts missiles, a deep-water port, aircraft hangars, and a 3,000-meter airstrip.

Subi Reef, previously submerged at high tide before Chinese reclamation, is classified internationally as a low-tide elevation and thus not entitled to a territorial sea.

“One of the ironies is that China’s interest in annexing Sandy Cay is about buttressing the legality of their claims to nearby Subi Reef, now host to a major artificial port and airfield,” said Euan Graham, a regional security expert at the Australian Strategic Policy Institute, on X.

The Philippines has yet to issue a formal response to the Chinese coast guard’s operation at Sandy Cay.

The incident comes amid the largest-ever “Balikatan” military exercises between the United States and the Philippines, involving 17,000 personnel and full-scale battle simulations.

In Zambales province Sunday, journalists witnessed the US Marine Corps’ new MADIS short-range air defense system and the Philippine SPYDER missile system successfully intercept drones during a coastal defense drill.

“MADIS is short-range. SPYDER is more of a medium-range capability and they both engaged different threats,” said Matthew Sladek, commander of the US 3rd Littoral Anti-Air Battalion.

“The more we work together, that only … enhances our collective lethality,” Sladek said, emphasizing the strength of the alliance.

Chinese warships, including the aircraft carrier Shandong, have been sighted near Philippine waters since the Balikatan exercises began last week.

On April 22, the Shandong was detected just 2.23 nautical miles southwest of the Babuyan Islands in northern Philippines, the Philippine Navy reported.

On Saturday, three other Chinese vessels were spotted approximately 60 kilometers from Zambales, intensifying maritime monitoring efforts by Manila.

US Defense Secretary Pete Hegseth recently told an audience in Manila that the United States is “doubling down” on its alliance with the Philippines due to “threats from the Communist Chinese.”

China’s Foreign Ministry has condemned the Balikatan drills, with spokesperson Guo Jiakun calling them a “blow to regional stability.”

Balikatan exercises are set to continue Monday, with troops conducting simulated defenses against enemy landings along Palawan Island, near the contested South China Sea waters.

The South China Sea remains one of the world’s most volatile maritime flashpoints, with Beijing’s expansive “nine-dash line” claim overlapping the exclusive economic zones of Vietnam, Malaysia, Brunei, Indonesia, and the Philippines.

An international arbitration ruling in 2016 invalidated China’s sweeping claims, but Beijing has refused to recognize the decision.