"On October 22, the Philippines, ignoring repeated warnings by China, sent two transport ships and two coast guard ships for an unauthorized invasion into the waters near the Ren’ai Reef of the Chinese Nansha Islands," the CCG said in a statement on WeChat.
The Philippine ships "unsafely approached" a Chinese ship, which resulted in a light collision, according to the statement.
"Responsibility [for the incident] lies entirely with the Philippines," the CCG said.
The CCG added it would continue carrying out law enforcement activities in waters "under China’s jurisdiction in accordance with the law."
The territorial affiliation of a number of islands in the South China Sea has been the subject of disputes between China and several other Asia-Pacific countries for decades. Significant oil and gas reserves have been discovered on the continental shelf of those islands, including the Paracel Islands, the Spratly Islands, Thitu Island and Scarborough Shoal. Vietnam, Brunei, Malaysia, Taiwan, and the Philippines are involved in the disputes to some extent.