The two Chinese vessels were identified by other defense sources, who asked not to be identified, as “maritime surveillance vessels.”
The vessels were reported to be some six nautical miles west of Ayungin Shoal since Tuesday afternoon.
According to the source, the information about the Chinese presence “has been relayed to proper authorities,” including Malacañang and the Department of Foreign Affairs.
Wescom spokesperson Lt. Cherry Tindog confirmed that the regional military command has received reports about the Chinese vessels but declined to issue additional information concerning the reported intrusion.
Ayungin Shoal, also known internationally as Second Thomas Reef, is one of the reef formations within the six islands where Philippine troops are present and is considered by the country as part of the municipality of Kalayaan.
It is closest to Mischief Reef, which until 1995 was occupied by the Philippines until the Chinese built a fortification on it.