Ayungin Shoal

Washington has once again affirmed that it has a treaty obligation to defend the Philippines against any armed attack in the contested waterway.

While minor, the two collisions demonstrate the dangers inherent in Beijing’s campaign of escalation in the South China Sea.

The stand-off is just the latest to take place at Second Thomas Shoal, a Philippine-occupied feature in the South China Sea.

Vice Adm. Alberto Carlos' comments come two days after the Philippine Coast Guard removed a barrier that Chinese ships had installed at the disputed Scarborough Shoal.

The move follows an incident last month in which a Chinese vessel forcibly prevented the resupply of Filipino forces on the disputed Second Thomas Shoal.

The atoll in the South China Sea has been subject to what some observers have characterized as a Chinese blockade.

Government officials, including two former presidents, have denied Beijing's claim that Manila made an agreement to remove the ship from the disputed shoal.

Enrique Manalo's comments come at a time of growing tension over Second Thomas Shoal, a Philippine-occupied atoll in the Spratly Islands.

The announcement comes at a time of increased Chinese assertiveness in disputed waters.

This is the second time this year that Huang has been summoned following stand-offs in the vicinity of Second Thomas Shoal.

The Philippine Coast Guard claims that a Chinese vessel used a high-powered water cannon in order to prevent the resupply of the Philippine forces stationed on Second Thomas Shoal.

As relations between Manila and Washington rapidly improve, Beijing is upping the intensity in disputed parts of the South China Sea.