China coast guard monitors Philippine patrol boats in Sabina Shoal

China's coast guard said it was monitoring Philippine patrol and fishing vessels that have gathered around the contested Sabina Shoal, citing China's "indisputable sovereignty" over the Spratly Islands in the South China Sea.

China's coast guard had been monitoring the vessels since Saturday, spokesperson Gan Yu said in a statement late on Sunday.

Gan said patrol boats from the Philippine Fisheries and Aquatic Resources Bureau and multiple fishing boats have gathered in the waters near a Philippine ship which, China has said was "illegally stranded" at the shoal.

The stranded ship "violates" China's territorial sovereignty and maritime rights and interests, and "undermines" peace and stability in the South China Sea, the Chinese coast guard reiterated.