Two Philippine Coast Guard (PCG) vessels were intercepted by a China Coast Guard (CCG) ship and at least six maritime militia vessels near Ayungin (Second Thomas) Shoal in the West Philippine Sea (WPS), an American maritime expert said on Sunday.

Ray Powell, a former military officer and defense attaché from the United States, said a CCG vessel with bow number 5203 obstructed the PCG’s BRP Cabra and BRP Cape Engano when these were passing 14 nautical miles east of Ayungin Shoal.

Powell detailed the latest confrontation between the CCG and the PCG in his post on X, formerly Twitter.

According to Powell, the BRP Cabra and BRP Cape Engano illuminated their automatic identification system broadcasts around midnight, 18 nautical miles south of Ayungin Shoal.

These, he said, may have prompted China to intercept the PCG vessels “to bolster blockade around the shoal while the CCG 5203 went south and first interdicted the two Philippine vessels at 0700,” he added.

“They (two PCG ships) have been intercepted by China Coast Guard 5203,” said Powell, adding that the the six Chinese maritime militia vessels then closely shadowed the PCG vessels.

Ayungin Shoal is where the Philippine Navy’s commissioned vessel BRP Sierra Madre was grounded in 1999, serving as one of the country’s military outposts in the WPS. China claims the shoal, which it calls Ren’ai Jiao, as part of its Nansha Qundao region.

The Philippines maintained its sovereignty over the shoal as affirmed by the 2016 Arbitral ruling. Ayungin Shoal is located 105 nautical miles west of Palawan and lies within the country’s 200-mile EEZ, logged as part of the Philippine continental shelf.

Asserting its vast claims over almost the entire South China Sea, Beijing deployed its CCG’s vessel 5901, the world’s largest coast guard ship called “the Monster ship,” to anchor within the Philippines’ exclusive economic zone in WPS last 3 July.

PCG spokesperson for the WPS, Commodore Jay Tarriela, said the CCG’s 165-meter Monster ship was trying to “intimidate” the country’s BRP Teresa Magbanua, conducting maritime patrols, to leave the Escoda (Sabina) shoal.