Satellite images show China is building an island on a reef in the Truong Sa (Spratly) Islands, over which Vietnam claims sovereignty, large enough to accommodate what could be its first offshore airstrip in the South China Sea, a leading defense publication said on Friday.
The construction has stoked concern that China may be converting disputed territory in the mineral-rich archipelago into military installations, adding to tensions waters also claimed by Taiwan, Malaysia, the Philippines, Vietnam and Brunei.
IHS Jane's said images it had obtained showed the Chinese-built island on the Fiery Cross Reef to be at least 3,000 meters (1.9 miles) long and 200-300 meters (660-980 ft) wide, which it noted is "large enough to construct a runway and apron."
The building work flies in the face of U.S. calls for a freeze in provocative activity in the South China Sea, one of Asia's biggest security issues. Concern is growing about an escalation in disputes even as claimants work to establish a code of conduct to resolve them.
Dredgers were also creating a harbor to the east of the reef "that would appear to be large enough to receive tankers and major surface combatants," it said.
The land reclamation project was China's fourth in the Spratly Islands in the last 12 to 18 months and by far the largest, IHS Jane's said. It based its findings on images taken on Aug. 8 and Nov. 14 showing that dredgers had created a land mass almost the entire length of the reef.
It said Fiery Cross Reef was previously under water with its only habitable area a concrete platform built by China's navy. It said that structure was home to a Chinese garrison and had a pier, air-defense guns, anti-frogmen defenses, communications equipment, and a greenhouse.
Beijing has rejected Washington's call for all parties to halt activity in the disputed waters to ease tensions, saying it can build whatever its wants in the South China Sea.
Hong Kong media have reported that China is planning to build an air base on Fiery Cross Reef. In August, the deputy head of the Chinese Foreign Ministry's Boundary and Ocean Affairs Departments said he was unaware of any such plans.