July 20 (UPI) -- The Philippine military accused China of beating and injuring a Philippine Navy sailor with a wooden baton in the latest seaborne confrontation between the two nations over a submerged reef in the disputed South China Sea.

The incident occurred Monday morning near the BRP Sierra Madre, a derelict warship the Philippines intentionally grounded on the Second Thomas Shoal, a reef both countries lay claim to and which the Philippines calls Ayungin Shoal and China, Ren'ai Jiao.

The Armed Forces of the Philippines said in a statement that a China Coast Guard rigid-hull inflatable boat with eight people on board unlawfully approached the BRP Sierra Madre and took pictures and video of it.

While two AFP rubber boats drove it away, China Coast Guard personnel on the boat struck a Philippine Navy sailor on his head with a wooden baton. The man suffered a deep gash on his scalp, according to a picture shared online by Philippine Coast Guard spokesperson Jay Tarriela.

Video of the incident posted online by Tarriela shows some China Coast Guard members aboard a larger boat swinging long sticks down upon members of the Philippine Navy in a smaller rubber boat.