Both countries have planted flags on a collection of sand bars, extending the clash over the area between Beijing and Manila, a U.S. ally

China and the Philippines have each unfurled their national flags on tiny sandbars in the South China Sea, staking competing sovereignty claims in strategic waters seen as a potential flashpoint for global conflict.

The standoff over Sandy Cay, which lies close to military outposts built by both Beijing and Manila, was the latest between the two nations.