Philippines President Ferdinand Marcos Jr said on Wednesday new rules outlined by China's coast guard that could result in the detention of foreigners in the South China Sea were an escalation and "worrisome".

Chinese state media said on Sunday that personnel on a Philippine ship pointed guns at China's Coast Guard in disputed waters of the South China Sea last month.

Philippines President Ferdinand Marcos Jr said on Wednesday new rules outlined by China's coast guard that could result in the detention of foreigners in the South China Sea were an "escalation" and "worrisome".

The Philippines have warned China that it would consider any Filipino soldier killed by a Beijing water cannon to be an “act of war" amid heightened tensions in the region.

Footage released by the state broadcaster CCTV appears to show troops stationed on a grounded warship pointing rifles at a Chinese vessel

The China Coast Guard (CCG) has been accused of seizing and dumping overboard food and other supplies meant for Filipino troops stationed at a remote outpost in Ayungin (Second Thomas) Shoal, and allegedly obstructing a medical evacuation of ailing soldiers.

Philippine president Ferdinand Marcos Jr has suggested his country's stand-off with China could spiral into war if a Filipino citizen were killed in what have been increasingly violent confrontations with the Chinese coast guard.

Tensions between Beijing and Manila have escalated again. Chinese state media claims that Filipino crew members aboard a vessel near the disputed Second Thomas Shoal aimed their weapons at a Chinese Coast Guard ship,

Australian Deputy Prime Minister Richard Marles has called actions by Chinese vessels in the West Philippine Sea like the use of water cannons and the ramming of Philippine vessels a "serious escalation of tensions" and stressed that the move is inconsistent with United Nations Convention on the Law of the Sea (UNCLOS) and the final and binding 2016 South China Sea arbitration ruling.