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.

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.

Tensions are escalating in the South China Sea as China's navy conducted patrols, accusing the Philippines of causing disturbances. Simultaneously, the U.S. and Philippines conducted joint air force missions.