FILE PHOTO: Chinese Coast Guard vessels patrol near a fishing boat in a disputed area of the South China Sea. © Reuters / Erik De Castro

The Philippine government has accused the Chinese Coast Guard of unleashing water cannon on two supply ships in a disputed stretch of the South China Sea, claiming its boats were blocked and forced to turn around.

Manila�s Department of Foreign Affairs detailed the encounter in a statement on Wednesday, alleging that a pair of supply boats en route to the Ayungin Shoal - also known as the Second Thomas Shoal - were stopped by three Chinese vessels and water cannoned before they could reach their destination.

Fortunately, no one was hurt; but our boats had to abort their resupply mission, Foreign Affairs Secretary Teodoro Locsin said, adding that the department had conveyed its outrage, condemnation and protest of the incident to Beijing�s envoy to the Philippines, Huang Xilian.

The acts of the Chinese Coast Guard vessels are illegal. China has no law enforcement rights in and around these areas. They must take heed and back off.

Though both China and the Philippines claim territorial rights to the Ayungin Shoal, The Hague�s Permanent Court of Arbitration ruled in the latter country�s favor in 2016. And despite Chinese objections, the Philippines has occupied the area for much longer, after its military purposely grounded a naval vessel on the shoal in 1999.

Manila was also quick to note that the supply ships are covered by the Philippines-United States Mutual Defense Treaty, a pact inked with Washington in 1951 that calls for a US military response to any attack on the country, including island territories under its jurisdiction in the Pacific Ocean, its armed forces, public vessels or aircraft.

Beijing so far has not commented on the alleged run-in.