Satellite images revealed a “new structure” on Bombay Reef in the Paracel Islands, beefing up the superpower’s already heavy presence in the disputed waters. The new construction, which has appeared in the last three months features a 90ft long and 40ft wide platform raised from the water. And also boasts a radar dome measuring 20ft in diameter, with solar panels covering more than 1,300 square feet.
China has been fortifying several reefs and atolls, chiefly on the Spratly Islands.
Rival claimants, including Taiwan and Vietnam, have voiced their concern about developments.
The US and its allies have flown or sailed near to the structures as part “freedom of navigation” exercises, and US researchers say the building on Bombay Reef, which is equipped with a solar panel array and radar system, could be quickly replicated on islands elsewhere in the South China Sea.
In August, Chinese military ordered a US Navy plane flying over an island in the South China Sea to “leave immediately”.
The US Navy P-8A Poseidon jet was flying at 16,500 feet to get a view of low-lying coral reefs that have been turned into garrisons with five-storey buildings, large radar installations, power plants and runways sturdy enough to carry large military aircraft.
During the flight that was giving journalists from CNN a rare look at the islands, the crew was warned six times by the Chinese military to get out of their territory.
A spokesman for the Centre for Strategic and International Studies (CCIS) said: “The development is interesting given Bombay Reef’s strategic location and the possibility that the structure’s rapid deployment could be repeated in other parts of the South China Sea.”
The American group believes the structure is likely to be linked to military surveillance.
Bombay Reef is near key shipping lanes running between the Paracels and the Spratly Islands, so it is ideally placed to monitor sea traffic.
The CCUIS said China could build a permanent facility quickly “without the environmental destruction and reputational damage that accompanied the earlier island-building campaign”.
China has rejected all criticism, insisting building in the area is its prerogative.
Earlier this month, the US also urged China to halt the militarisation process.
Geng Shuang, a spokesman for the Chinese foreign ministry, denied all knowledge of the work on Bombay Reef.
The development coincides with the publication of the International Institute for Strategic Studies’ (IISS) Strategic Survey 2018, which identifies China as one of a number of countries practising “tolerance warfare” with its approach to the militarisation of some of the South China Sea’s archipelagos.
A statement issued by the IISS to accompany its new annual report warned: “China’s militarisation of many of the islands and implied threats intimidate regional neighbours, and aim to limit their respective claims and activities in the region.
“Developing counter-strategies to these ‘tolerance warfare’ techniques will require building domestic resilience and intensifying regional consultations among like-minded states to design robust common responses.”