MANILA, Philippines — The Philippines accused China on Tuesday of intimidating its fishermen at a disputed South China Sea shoal, and normalizing an “illegal presence,” after Beijing sent its largest coast guard vessel into Manila’s maritime zone.

A Philippine helicopter followed a China Coast Guard (CCG) monster ship lurking off the coast. Footage shows the Philippine Coast Guard (PCG) Islander helicopter issuing a radio challenge to CCG vessel 5901 sailing near the shores of Zambales province on3.

The Philippines said a huge Chinese coast guard ship widely known as the “Monster” has returned to its exclusive economic zone in the South China Sea, prompting its own coast guard vessel to approach and issue a radio challenge.