China’s military said it drove away three Philippines aircraft “illegally” flying over the disputed Spratly Islands, marking the second aerial incident this week involving Beijing and Manila in the South China Sea.

The South China Sea is an important shipping route that holds significant oil and gas reserves.

"The Philippines has no major external security threats, but has turned itself into a country that undermines regional peace and stability through a militarization carnival," said Ding Duo, director of the Research Center for International and Regional Issues at the National Institute for South China Sea Studies.