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.

Chinese coastguard officers have seized a strip of land in the South China Sea in a major escalation of a territorial dispute with the Philippines. State broadcaster CCTV released images showing four officers in black uniforms holding the Chinese flag whilst standing on Sandy Cay in the Spratly Islands.