A Philippine vessel has been anchored at the Sabina Shoal to "catch and document the dumping of crushed corals over the sandbars", Tarriela said, citing the "alarming" presence of dozens of Chinese ships, including research and navy vessels.

China has deployed vessels and divers to explore a South China Sea shoal for reclamation, according to the Philippines, in another incident that could escalate the two nations’ maritime dispute.