The China Coast Guard took action over the weekend against Philippine ships that approached a Philippine patrol vessel staying illegally near China's Xianbin Reef in the South China Sea, according to a Chinese spokesman.

In a statement released on Sunday night, Coast Guard spokesman Gan Yu said that Chinese ships monitored and warned off vessels from the Philippines' Bureau of Fisheries and Aquatic Resources. These vessels had gathered around the Philippine Coast Guard ship BRP Teresa Magbanua, the largest and most advanced ship in the PCG's fleet.

The Teresa Magbanua has been staying illegally near the Xianbin Reef of China's Nansha Islands since mid-April.

"China has indisputable sovereignty over the Nansha Islands and their adjacent waters," Gan said. He added that the Philippine ships had infringed on China's sovereignty and maritime rights, violated the Declaration on the Conduct of Parties in the South China Sea, and jeopardized regional peace and stability.

"The China Coast Guard will, as always, conduct rights protection and law enforcement activities in the waters under Chinese jurisdiction, firmly safeguarding national sovereignty and maritime interests," Gan stated.