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.

BEIJING (AP) — China says six Filipinos landed on a tiny outcropping that both countries claim in the South China Sea, days after photos emerged of Chinese coast guard officers displaying a Chinese flag on the same group of sandbars.

The Philippine military responded to the landing of Chinese forces on Sandy Cay reef by carrying out a similar operation, reports the Philippine News Agency. On April 27, the National Operational-Tactical Group West Philippine Sea carried out an interagency maritime operation.