BEIJING 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 (Aug 3), spokesperson Gan Yu said in a statement late on Sunday (Aug 4).

Gan said patrol boats from the Philippine Bureau of Fisheries and Aquatic Resources (BFAR) and multiple fishing boats have gathered in the waters near a Philippine ship which China has said was "illegally stranded" at the shoal and that "violates" China's territorial sovereignty and maritime rights and interests in the region.

In response, the Philippine Coast Guard (PCG) said China has no reason to complain about its vessels because Sabina Shoal is within its own exclusive economic zone (EEZ).

PCG spokesperson Jay Tarriela also said the ship the Chinese say is "illegally stranded", the BRP Teresa Magbanua, "was purposely deployed there to safeguard our EEZ and whether it will stay longer there is not their concern."

On Sunday, the PCG said it has deployed inflatable boats from Teresa Magbanua to support the fisheries bureau while it distributed fuel to Filipino fishing boats at the shoal.

China refers to Sabina Shoal as Xianbin Reef, while the Philippines calls it Escoda Shoal. It is an atoll located 150km (93 miles) from the western Philippine island of Palawan.

The PCG has accused China of building an artificial island at the shoal. China has said the charge was groundless.

Beijing and Manila have been embroiled for a year in a heated stand-off over competing claims in the South China Sea, where US$3 trillion worth of trade passes annually.

Manila reached a provisional arrangement with China for resupply missions in the South China Sea last month in an attempt to ease tensions and manage differences. The details of the deal have not been made public.

China claims almost all of the vital waterway, including parts claimed by the Philippines, Brunei, Malaysia, Taiwan and Vietnam. The Permanent Court of Arbitration ruled in 2016 that Beijing's claims had no basis under international law.

  - Reuters