China has rejected US allegations on Sunday that Chinese fighter jets acted in an "unsafe and unprofessional" manner when they intercepted a US surveillance plane over the South China Sea.

A pair of Chinese J-10 fighter jets intercepted a US Navy P-3 that was flying in international airspace 150 miles (240 km) southeast of Hong Kong on Wednesday, according to Pentagon spokesman Commander Gary Ross.

One Chinese jet flew in front of the Navy plane, limiting its ability to maneuver, Ross said in a statement.

"We continue to review the facts of this incident and will convey our concerns through appropriate channels with the Chinese government," he said.

China's Defense Ministry rejected the US account of the interception as inaccurate.

The Chinese jets operated in a professional and safe manner, the ministry said on its official account on China's Twitter-like Weibo.

The incident is the latest in a series of similar disputes in recent years over the disputed waterway. China claims much of it as its own, even areas that are much closer to some of its smaller neighbors, including Vietnam, the Philippines and Malaysia.

Beijing accuses Washington

Beijing also accused Washington of trespassing last week after it sailed a warship near a reef claimed by Beijing in the South China Sea.

The warship sailed within 12 nautical miles (22 km) of an artificial island built up by China in the South China Sea in what was the "first freedom of navigation" exercise under President Donald Trump.

These actions "infringed on our sovereignty and security, endangering the safety of frontline personnel of both sides," China's Defense Ministry said in its statement.

"The behavior is the root cause of the military security problems in maritime and sky areas between US and China," it said, adding: "China's armed forces will resolutely perform their duties and resolutely safeguard our sovereignty and security."  

Beijing has rapidly built up reefs in the South China Sea into artificial islands capable of hosting military planes.

The US has challenged China's annexation of these islets and advocated a diplomatic settlement to the disputes, arguing that Beijing's actions threaten freedom of navigation and overflight.

The latest tensions come ahead of a major regional security summit in Singapore this week.

bik/tj (AFP, Reuters)