ON August 5 six China Coast Guard (CCG) vessels, 12 Chinese maritime militia vessels and three People's Liberation Army-Navy (PLA-N) vessels disrupted the Philippine Coast Guard's (PCG's) delivery of supplies to the Philippine military contingent on board the BRP Sierra Madre on Ayungin (Second Thomas) Shoal.

Sierra Madre is the 100-meter World War 2 vessel grounded in Ayungin since 1999, and occupied by less than a dozen Philippine Navy men and Marines whose mission is to fly the Philippine flag and assert symbolic Philippine sovereignty over the atoll.