FEATURE | Beijing expands reach in disputed South China Sea with new man-made island

Woody Island has served as the traditional administrative centre for China in the South China Sea, housing at times jet fighters and surface-to-air missiles. Triton Island, also in the Paracels, hosts extensive long-range surveillance devices.

China has occupied all the Paracels since 1974, when it forced off the navy of the former South Vietnam. Vietnam, which claims the entire grouping as its own, has moved in recent years to expand its own network of bases in the Spratlys.

Vietnam's foreign ministry did not immediately respond to Reuters requests for comment. It has previously asserted its sovereignty claims to Antelope, saying in March it, "resolutely opposes such actions (and) has made representations".

Antelope could also help support any bid by China to create so-called bastions or protected ocean areas in the South China Sea to defend its nuclear-armed ballistic missile submarines, said Singapore-based security scholar Collin Koh.

Koh said the island buildup, likely to house extensive surveillance equipment, could potentially complicate submarine operations by the United States and Vietnam, which are both active in the area.