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.

US peace envoys meet Zelenskyy in Kyiv after Putin talks
US targets three Iranian oil vessels after attack on Navy ships
Four killed in Israeli strikes on southern Lebanon
Indonesia's Anak Krakatau eruption halts flights, schools, fishing
Putin says US-Russia contacts beneficial as talks begin with Witkoff and Kushner
Chinese national rescued from Nepal tunnel 10 days after flash flood
US envoys Witkoff, Kushner arrive in Moscow for talks on peace in Ukraine
One dead, 11 people missing after mudslide in China's Jiangxi province
