Coast guard ships equipped with a water cannon should not use it to harass other vessels but to save lives at sea, a Philippine Coast Guard (PCG) official said.

Commodore Jay Tarriela, PCG spokesperson for West Philippine Sea (WPS), made the remark in response to the blatant use of water cannon by a China Coast Guard (CCG) ship on Philippine vessels during a recent resupply mission by the Armed Forces of the Philippines (AFP) in Ayungin (Second Thomas) Shoal.

"In terms of the rules [on] the use of force, I think the water cannon that the Chinese has been using against the PCG vessels or even the resupply boats is something that is not applicable for such usage," Tarriela said.

The AFP made the 12th resupply mission to bring fresh provisions for troops stationed at BRP Sierra Madre on Nov. 10 while the PCG deployed three of its ships to support them. 

BRP Sierra Madre, a World War II warship by the Philippine Navy, was ran aground off Ayungin Shoal to serve as a military outpost and stake the Philippines' claim in the disputed atoll.

However, a CCG vessel with bow number 5203 fired a water cannon against motor launcher (M/L) Kalayaan, one of the two supply boats chartered by the AFP for the mission, to drive it away and prevent it from reaching Ayungin Shoal.

PCG Commandant Adm. Ronnie Gil Gavan earlier condemned CCG's use of water cannon against the much smaller boat as well as their "unprovoked acts of coercion and dangerous maneuvers," saying it "has put the lives of our personnel at risk."

Normally, a military ship may use its water cannon to shoo away another vessel it considers as a threat but such is not the case for coast guard vessels, which are civilian in nature.

Tarriela explained that the PCG only uses a water cannon on their ships ecxlusively for firefighting operations.

Asked what the PCG would do if the CCG deploy anew its water cannon during the next resupply mission, Tarriela said that Filipino coast guardians were advised to practice restraint and avoid escalating the tension in the WPS.

"We just have to make sure that our personnel and vessel will not be affected. They have to make sure no harm will be done to our personnel," he said.

"It's either we move away from them [CCG vessels] to protect our personnel and make sure we are not going to be triggered to escalate the tension," he added.