U.S. warship sails within 12 miles of China-claimed reef

Arleigh Burke-class guided-missile destroyer USS Dewey transits the South China Sea May 6, 2017. Kryzentia Weiermann/Courtesy U.S. Navy/Handout via REUTERS

WASHINGTON (Reuters) - A U.S. warship carried out a "manoeuvring drill" when it sailed within 12 nautical miles of an artificial island built up by China in the South China Sea, to show Beijing it was not entitled to a territorial sea around it, U.S. officials said on Thursday.

The operation near Mischief Reef on Thursday, Pacific time, among a string of islets, reefs and shoals over which China has disputes with its neighbours, was the boldest U.S. challenge yet to Chinese island-building in the strategic waterway.