MANILA, Philippines — The Philippine military said Chinese coast guard personnel aboard a motorboat repeatedly struck a Filipino sailor on the head with a wooden baton Monday in a disputed shoal in the South China Sea, injuring him and damaging his smaller vessel.

The assault was captured on video by other Filipino sailors in the hotly disputed Second Thomas Shoal and set off angry condemnations by Philippine officials. They praised the Filipino navy personnel, saying they did not do anything that could have caused an escalation.

Chinese officials did not immediately issue a statement on the incident, but they have repeatedly restated their claim to the shoal and to virtually the entire South China Sea. They have demanded that Manila pull away a long-marooned and now rusting navy ship, the BRP Sierra Madre, which is manned by Filipino navy personnel and serves as a fragile territorial outpost.

The Philippine military said a Chinese coast guard inflatable boat carrying eight personnel was deployed from a ship and approached the BRP Sierra Madre within close range and maneuvered around while its occupants took pictures and video.

Filipino sailors aboard two rubber boats asked the Chinese to back away in a non-confrontational manner. “The Chinese coast guard vessel personnel reacted violently and aggressively by striking a Philippine Navy personnel on the head with a wooden baton, causing injury and damaging the navy rubber boat,” the Philippine military said.

The extent of the Filipino sailor’s injury was being assessed to determine if he needed to be medically evacuated, it said.

“No act of coercion or aggression will deter us from carrying out our constitutional mandate or exercising the Philippines’ lawful rights in the West Philippine Sea,” the military said, using the Philippine name for the South China Sea.

“The latest act of violence and harassment committed by the China coast guard against Philippine navy personnel … adds to a clear pattern of provocative and hostile behavior and further contributes to the People’s Republic of China’s deficit of trust and credibility,” the Department of National Defense said in a statement.

The Philippines deliberately beached the Sierra Madre in the shallows of the Second Thomas Shoal in 1999 to serve as a territorial outpost. China, which also claims the shoal, later surrounded the atoll with its ships in a tense territorial standoff that has dragged on for years.

The long-simmering territorial disputes, which also involve, Brunei, Malaysia, Vietnam and Taiwan, is high in the agenda of annual talks in Manila this week between foreign ministers of the Association of Southeast Asian Nations and their Chinese counterpart, Wang Yi.

Both sides have been negotiating a nonaggression pact that aims to prevent a major armed conflict that could draw in the United States, which has vowed to help deter growing Chinese aggression and defend freedom of navigation in the busy waterway.