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 voice said: “US military aircraft, this is China ... leave immediately and keep out to avoid any misunderstanding.”
https://www.express.co.uk/news/world...na-Sea-US-Navy