The recent "joint patrol" in the South China Sea, organized by the Philippines and involving non-regional countries, has severely undermined regional peace and stability, said Tian Junli, a spokesperson for the Chinese People's Liberation Army (PLA) Southern Theater Command, on Saturday.

The statement from Tian came after the Philippines conducted the so-called joint patrol from October 30 to 31.

"The recent developments further confirm that the Philippines is acting as a troublemaker on the South China Sea issue and a disruptor of regional stability," Tian said.

The spokesperson emphasized that the PLA Southern Theater Command had mobilized forces to closely track and monitor the activities, adding that all such actions seeking to stir up trouble in the South China Sea "are under firm control."

Tian said that the theater command's troops remain on high alert and will resolutely defend national sovereignty and maritime rights and interests.