China 'building runway' on island
China is building an airstrip on an artificially created island in a disputed section of the South China Sea, according to independent analysts.
The US warned the move could raise tensions in the area.
Satellite images of Fiery Cross Reef taken on March 23 show a runway more than 500 metres (1,640ft) long as well as paved sections of apron, according to defence group IHS Jane's.
The US said China is carrying out eight such land reclamation projects in the area.
Jane's said the island is already big enough for a runway 3,000 metres (9,500ft) long that would be able to accommodate air force planes.
China already operates a runway on Woody Island to the west of Fiery Cross Reef, which is also claimed by Vietnam, the Philippines and Taiwan, and another island it is creating could also be big enough to accommodate a runway.
The airfield construction also was mentioned by the commander of US forces in the Pacific at a congressional hearing on Wednesday.
Admiral Samuel Locklear said the reclamation work would allow China to exert more influence in the contested region and possibly deploy military assets such as long-range radar and advanced missile systems.
China claims virtually all of the South China Sea and its island chains. Malaysia and Brunei also claim waters and islands in the area.
At a Friday briefing, foreign ministry spokesman defended the island reclamation work, which China says is largely to improve living conditions for people in the area and help with weather forecasting and search and rescue work.
Such work is "lawful, justifiable and reasonable", the spokesman said. "It does not target or impact on any other country and we hope that relevant parties can have a correct understanding on that."