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 China Coast Guard “implemented maritime control and exercised sovereign jurisdiction” over Sandy Cay this month, the military channel of state broadcaster CCTV reported on Saturday. It said coastguard officers had unfurled the Chinese flag to declare sovereignty over the reef in the Spratly Islands,

China's coast guard said Sunday it had "dealt with" a situation involving six Filipinos who it accused of illegally landing on a disputed reef, after Beijing's state media said the tiny sandbank had recently come under Chinese control.