A Chinese Coast Guard water cannon attack allegedly damaged the Philippine flag hoisted on a government ship during a resupply mission in the South China Sea.

The aggressive Chinese vessel CCG-3305 fired a high-pressure blast of water at the Philippines' BRP Datu Bankaw delivering supplies to the disputed Scarborough Shoal on April 30.

The attack reportedly hit the Philippine flag and damaged communication and navigation equipment onboard the civilian vessel.

Philippine authorities said they were mulling filing a diplomatic protest against China.

Philippine Department of Foreign Affairs Spokesperson Ma. Teresita Daza said: 'I think we have to investigate if the flag was targetted. It's difficult to actually already say that it should be protested.'

Expansionist China currently lays claim over almost the entire South China Sea, one of the world's busiest sea lanes. But a United Nations-backed tribunal in 2016 deemed its claims groundless.

The Communist rogue state - accused of genocide for its crimes against the Uyghur population - has been steadily increasing its influence in recent years through investment in developing countries.

Senators have taken steps to prevent the state's influence in the United States by battling to ban the social media app TikTok.