China's military conducted war games in the disputed South China Sea this week, an official newspaper said Friday, as tensions simmer over Beijing's island-building in the region.

China insists it has sovereignty over virtually all of the resource-rich South China Sea, conflicting with the various claims of Vietnam, Malaysia, the Philippines, Taiwan and Brunei.

Warships, submarines, early warning aircraft and fighter jets were deployed in exercises that occurred over a "range of several thousand kilometres", the People's Liberation Army Daily said.

They were split into red and blue teams that practised deflecting anti-ship missile attacks and scenarios that included one of an accidental strike on a third-party commercial ship, it added.

"Only by experiencing a variety of difficult situations can one not panic in the midst of war and win," the paper quoted Li Xiaoyan, deputy chief of staff of the South China Sea fleet and commander of the red team, as saying.

Last week, the US deployed for the first time a P-8 Poseidon spy plane in Singapore, with local diplomats saying the decision was likely aimed at sending a message to China about Washington's resolve to oppose what they describe as Beijing's aggressive regional policy.

The US is critical of China building artificial islands in the disputed sea, and has flown B-52 bombers and sailed a guided-missile destroyer near some of the constructions in recent months.

Washington angered Beijing in October when a US warship sailed close to artificial islets that China is building out into military bases, in what the US called a "freedom of navigation" exercise.

Washington has said China's transformation of the geographical features in the Spratly Islands poses a threat to freedom of navigation in the critical area.