The Philippines accused China on Tuesday of intimidating its fishermen at a disputed South China Sea shoal, and normalising an "illegal presence", after Beijing sent its largest coast guard vessel into Manila's maritime zone.

The Philippines said Tuesday it was alarmed by Chinese coast guard patrols which are growing closer to the country's shore.

The Philippines has lodged a diplomatic protest over the presence of Chinese coast guard vessels, including a “monster ship”, in its claimed exclusive economic zone, amid fears that Beijing wants to alter the status quo in the South China Sea.