The incident, which the Philippines said took place last month, involved a member of a small contingent of marines posted to guard the BRP Sierra Madre, a Philippine vessel grounded at the disputed Second Thomas Shoal,Second Thomas Shoal, the site of repeated confrontations with China this past year.
Coast Guard spokesperson Jay Tarriela said coast guard and navy rubber boats were harassed by the Chinese vessels, despite having informed them the operation was of a medical nature.
"The barbaric and inhumane behaviour displayed by the China Coast Guard has no place in our society," Tarriela said in a statement.
China's embassy in the Philippines did not immediately respond to a request for comment.
Tarriela said the Chinese coast guard "engaged in dangerous manoeuvres and even intentionally rammed the PN RHIB while transporting the sick personnel."
China claims almost the entire South China Sea, a conduit for more than $3 trillion in annual ship commerce, and has deployed hundreds of coast guard vessels as far as 1,000 km off its mainland to police what it says is its jurisdiction.
The Philippines and China have sparred repeatedly this past year near disputed features that fall in Manila's exclusive economic zone. China routinely accuses the Philippines of encroachment while Manila and its allies have condemned what they calls aggression by Beijing.
In 2016, the Permanent Court of Arbitration in the Hague said China's claims had no legal basis, a decision Beijing has rejected.
