China has redeployed its big Coast Guard vessel CG 5901, as The Monster'' in the exclusive economic zone but the Philippine Coast Guard (PCG) continues to monitor its presence despite ''adverse sea conditions with estimated wave heights of three to five meters.''

''The Chinese vessel has been kept at a considerable distance of approximately 95 nautical miles off the coast of Zambales,'' said Commodore Jay Tarriela, PCG spokesperson of the National Task Force the West Philippine Sea in a Viber message Sunday evening.

Shadowing the Chinese Coast Guard ship is the BRP Teresa Magbanua, one of the two biggest vessels of the PCG.

Radio challenges have been conducted ''to address the unlawful presence of the Chinese Coast Guard within the Philippines' Exclusive Zone,'' said Tarriela

''It is crucial for the Philippines to persistently challenge their presence to prevent the normalization of their illegal activities, which could ultimately lead to a successful alteration of the status quo,'' added Tarriela.

The Chinese vessels have been staying the area since last Saturday.

China Coast Guard ship 5901 replaced the smaller CG3301 on Saturday where was positioned 97 nautical miles off the coast of Zambales.