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.

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.

In response to a media inquiry regarding the Philippine National Security Council spokesperson’s claims about China Coast Guard (CCG) vessels in the South China Sea, Chinese Foreign Ministry spokesperson Guo Jiakun said on Tuesday that CCG conducts patrols in relevant waters in accordance with the law,

A Philippine security official says China is “pushing us to the wall” with growing aggression in the disputed South China Sea and warned that “all options are on the table” for Manila’s response, including new international lawsuits.

Growing tensions between China and the Philippines in the disputed Scarborough Shoal in the South China Sea are reaching a boiling point, Manila officials say.