US Navy begins patrol near China's man-made islands

The U.S. Navy sent a warship on Tuesday within 12 nautical miles of two artificial islands built by China in the South China Sea, a U.S. defence official told Reuters, in a challenge to China's territorial claims in the area.

The official said the patrol was carried out by the destroyer USS Lassen near Subi and Mischief reefs in the Spratly archipelago, features that were formerly submerged at high tide before China began a massive dredging project to turn them into islands in 2014.

"The operation has begun ... It will be complete within a few hours," said the official.