The Philippines said on Monday there was no truth to news reports that Beijing has seized control of a disputed reef in the South China Sea, after its personnel landed on the unoccupied sandbars and found no Chinese presence there.

The competing claims are reigniting tensions in the South China Sea and coincide with joint military drills between the U.S. and the Philippines.

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.