China Coast Guard (CCG) spokesperson Gan Yu said 34 individuals from the Philippines ignored China's warning and illegally boarded the Tiexian Reef on Thursday. The reef is located in the northern part of the Nansha Islands.

The CCG law enforcement officers investigated and handled the case in accordance with the law. "China has indisputable sovereignty over the Nansha Islands including the Tiexian Reef and its adjacent waters, with sufficient historical evidence and legal basis," Gan said in a statement published on Thursday. 

"The Philippines' actions infringe on China's territorial sovereignty, violate the Declaration on the Conduct of Parties in the South China Sea, and undermine peace and stability in the South China Sea," Gan said. 

The CCG opposes such illegal actions and will continue to carry out rights protection and law enforcement activities in waters under China's jurisdiction, in accordance with the law, Gan added.