File photo taken in July, 2016 shows Chinese H-6K bomber patrolling islands and reefs including Huangyan Island in the South China Sea. (Xinhua/Liu Rui)

The Chinese People's Liberation Army (PLA) Southern Theater Command on Wednesday held a combat patrol in the South China Sea in an apparent response to a joint exercise by the Philippines, the US, Australia and Canada in the region. The combat patrol is a move to defend China's territorial sovereignty and maritime rights while sending a warning to relevant parties not to fan the flames in the region, experts said. 

With the aim of testing troops' reconnaissance, early warning, fast maneuvering and joint strike capabilities, the PLA Southern Theater Command on Wednesday organized a joint combat patrol in waters and airspace near Huangyan Dao (also known as Huangyan Island) in the South China Sea, the theater command said in a press release on Wednesday. 

All military activities that stir up the situation in the South China Sea, create hotspot events and sabotage regional peace and stability are in complete control, the PLA Southern Theater Command said.

The PLA Southern Theater Command did not elaborate, but the Philippines, the US, Australia and Canada kicked off their first joint military exercise in the South China Sea on Wednesday to enhance interoperability among their forces, Reuters reported on Wednesday.

The two-day exercise involves naval and air force units, and follows the first Philippines-Japan joint exercise in the South China Sea last week, Reuters said.

PLA warplanes and warships routinely conduct exercise trainings in the South China Sea, so the PLA can immediately respond to any provocative moves or threats, a Chinese military expert who requested anonymity told the Global Times on Wednesday.

Zhang Junshe, another Chinese military expert, said that the Philippines-US-Australia-Canada joint drill is of symbolic significance only, attempting to show that countries such as the US are supporting the Philippines in its provocative moves.

Manila's approach of "inviting wolves into the house" not only attracts many external military forces in the South China Sea, but also negatively impacts the centrality of the ASEAN in regional security affairs, Ding Duo, a deputy director of the Institute of Maritime Law and Policy at China's National Institute for South China Sea Studies, told the Global Times.

Calling the US the biggest external factor that escalates tensions in the region, Ding said that the US' pushing of small multilateral mechanisms and bloc confrontation stems from its entrenched Cold War mentality and wrong perception toward China.