HONG KONG – China has completed the first phase of construction on Antelope Reef in the Paracels archipelago, building a man-made island in the hotly-disputed South China Sea that analysts say will form part of its largest military base.

Satellite images show the reclaimed feature in outline for the first time, with barges and dredgers having left after at least six months of work in the busy waterway.

The completion shows the South China Sea as an increasingly militarized arena of competition between China and the United States and its allies, as both sides jostle for advantages that could prove critical in any future conflict over Taiwan.