ABOARD BRP SINDANGAN -- The Philippines will not allow China to remove a Philippine military outpost in a fiercely disputed South China Sea shoal, a navy official said Wednesday, a day after four Filipino navy personnel were injured in a confrontation between Chinese and Philippine ships.
Philippine officials summoned a Chinese Embassy diplomat in Manila to convey a strong protest over the confrontation Tuesday off Second Thomas Shoal. A small Filipino navy contingent has stood guard on a long-marooned warship that has served as an outpost in the shoal since the 1990s.
Washington issued a warning after Tuesday's hostilities that it is obligated to defend the Philippines, its oldest treaty ally in Asia, if Filipino forces, ships or aircraft come under an armed attack anywhere in the South China Sea.
Philippine navy Commodore Roy Trinidad also said Filipino forces will not allow any structure to be erected in another hotly contested South China Sea area, Scarborough Shoal. China surrounded the vast fishing atoll northwest of the Philippines with coast guard and suspected militia ships in 2012 after a tense standoff between Chinese and Philippine ships.
"These are red lines for the Philippines, to the armed forces," Trinidad said at a news conference in Manila when asked what Chinese actions would be unacceptable to the Philippines in the disputed waters.
Trinidad said the administration of former President Rodrigo Duterte, who preceded current President Ferdinand Marcos Jr., established those "red lines," which delineate actions by China and any other rival claimant state that would spark fierce Philippine resistance in the disputed sea.
The latest flareup in the long-simmering disputes began when Chinese coast guard and suspected militia ships shadowed, surrounded and blocked two Philippine coast guard ships that were escorting two civilian motorboats manned by Filipino navy personnel.
They were on the way to deliver supplies and replacement navy and marine personnel to the BRP Sierra Madre, a navy warship that was deliberately grounded by the Philippine military in the late 1990s in the shallows of Second Thomas Shoal to serve as a territorial outpost.
China also claims the area and has surrounded the shoal with coast guard, navy and suspected militia ships to prevent Filipino forces from delivering construction materials to reinforce the Sierra Madre, which is encrusted with rust and slightly tilting but remains an actively commissioned navy ship, meaning any attack on it would be considered by Manila as an act of war.
After dawn on Tuesday, a Chinese coast guard vessel sideswiped one of the Philippine coast guard ships, the BRP Sindangan, where crewmen scrambled to lower rubber fenders along the side to avoid damage to the hull. Two Associated Press journalists and other media who were invited to travel on the patrol ship witnessed the tense confrontation.
Inviting journalists to join trips by Philippine ships to the area is part of a strategy adopted last year by the government to publicize China's aggressive actions in one of the world's most hotly contested waterways. China has reacted by providing its coast guard personnel with video cameras to contest Manila's version of the confrontations.
The Chinese coast guard said in its account of the incident that the BRP Sindangan had rammed its ship, although the journalists aboard the Philippine coast guard vessel saw the Chinese ship approach dangerously close before the collision.
Later, another Chinese coast guard ship blocked and then collided with a supply boat being escorted by the Philippine coast guard, Filipino officials said.
The supply boat was later hit by water cannon blasts from two Chinese coast guard ships. Philippine navy Vice Admiral Alberto Carlos was aboard the boat and witnessed the water cannon assault, which he said caused minor injuries to four navy personnel.
"The pressure was really intense," Carlos said. "It shattered the windshield of the boat and caused some injuries."
The damaged boat immediately returned to the western Philippine province of Palawan. The other supply boat managed to evade the Chinese coast guard blockade and delivered supplies to the Filipino forces guarding the shoal, Philippine officials said.
The two-decade-long territorial standoff sparked a series of confrontations between Chinese and Filipino forces last year, with the Philippines protesting dangerous maneuvers by Chinese coast guard vessels and China demanding that the Sierra Madre be towed away by the Philippines.
Information for this article was contributed by Jim Gomez of The Associated Press.