The Armed Forces of the Philippines  (AFP) on Tuesday said it continues to monitor Chinese vessels and a floating structure inside Bajo de Masinloc amid concerns over possible marine research activities.

AFP Public Affairs Office chief Col. Xerxes Trinidad said surveillance and documentation efforts are ongoing as part of efforts to assert Philippine sovereign rights in the West Philippine Sea.

The Philippine Coast Guard reported that the floating structure had been moved from the entrance of Bajo de Masinloc to inside the shoal.

Navy spokesperson Capt. Marissa Martinez said the military would continue monitoring developments but would not speculate on the structure’s purpose.

Trinidad said the AFP remains committed to documenting activities in the area, citing lessons from the 1995 occupation of Mischief Reef.

The Philippine Navy also reported monitoring 26 Chinese vessels in the West Philippine Sea from 9 to 15 June, consisting of 19 China Coast Guard ships and seven People’s Liberation Army Navy warships.

In 2016, an arbitral tribunal in The Hague ruled that China’s sweeping claims in the South China Sea had no legal basis under international law.