Satellite images showing surveillance balloons above the man-made Mischief Reef have been seen as further evidence of China’s militarisation of the strategic stretch of water which also is claimed by Brunei, Malaysia, the Philippines, Taiwan and Vietnam.
Defence analysts said the balloons were capable of carrying array radars, infra-red and optical sensors and electronic jamming and surveillance devices which could form an airborne warning and control system.
They said the balloons effectively completed an overlapping network of radars and satellites reaching far into the South China Sea to detect low-flying aircraft and small vessels and enabling Beijing to put the whole region in lockdown.
Mischief Reef is believed to boast bomb-proof aircraft hangars, underground fuel storage facilities and ammunition bunkers.
A recent report by the Asia Maritime Transparency Initiative, part of Washington’s Centre for Strategic and International Studies, said satellite images revealed missile shelters and radar and communications facilities were also under construction on Mischief Reef as well as Fiery Cross and Subi Reefs, also in the Spratly Islands.
The report said China had built four new missile shelters on Fiery Cross Reef to go with the eight already on the artificial island.
A large antennae array is being installed on Mischief Reef which analysts believe will boost Beijing’s ability to monitor the surroundings.
A large dome recently was installed on Fiery Cross and another is under construction, indicating a sizeable communications or radar system. Two more domes are under construction at Mischief Reef.
The think-tank report said: “Beijing can now deploy military assets, including combat aircraft and mobile missile launchers, to the Spratly Islands at any time.”
Washington has criticised China’s build-up of military facilities on the artificial islands and fears they could be used to restrict free movement along the important South China Sea trade route.
Beijing insists the recent installations are nothing more sinister than rescue and fishing stations.
China said the missions were designed out “to stir up trouble”.
China’s Foreign Ministry spokesman Geng Shuang said: “US actions have seriously undermined China’s sovereignty and security interests and damaged peace and stability in the South China Sea.
“China strongly opposes such actions and has lodged stern representations with the US.”
A spokesman for the People’s Liberation Army said: “We absolutely oppose any country using freedom of navigation and flight as an excuse to undermine China’s sovereignty and security.
“China will take all measures necessary to adamantly safeguard national sovereignty and peace and maintain peace and stability in the South China Sea.
“No matter what trickery the US pulls from its hat, the Chinese military has the resolution and capability to protect its national sovereignty and security as well as maintain peace and stability in the region.”