Tensions rise as US warship challenges China's South China Sea claims.

China has warned of "serious consequences" after the US Navy sailed a destroyer around the disputed Paracel Islands in the South China Sea for the second day in a row, in a move Beijing claimed was a violation of its sovereignty and security. The US called it a "freedom of navigation operation" challenging requirements from all three nations requiring either advance notification or permission before a military vessel sails by. China accused the US of "undermining the peace and stability of the South China Sea" with its actions.