Foreign Minister Yang Jiechi has rejected accusations that the Chinese government and military are behind cyber attacks on Western websites, calling for "rules and cooperation", instead of a cyberspace "war" or politics-driven smear campaigns.

Yang is the highest-level Chinese official so far to respond to recent hype in Western media about alleged military-backed hackers from China, fanned by a report from US Internet security firm Mandiant last month saying it had traced a host of cyber attacks to an address in Shanghai.

Yang was talking to reporters on the sidelines of the annual session of the National People's Congress, and described the claims as part of a politically motivated smear campaign.

"Those reports may have caught the eye of many people, but they are built on shaky ground," said Yang, voicing his opposition to "turn cyberspace into another battlefield, or capitalize on virtual reality to interfere in another country's internal affairs."

China's Ministry of National Defense had scorned the accusations as "unprofessional and false" shortly after the report was released. It also said China has never directly accused the US government of being behind the attacks even though its military computers suffered "a large number" of overseas attacks, with "a considerable number" of them originating from the US judging from the IP addresses.

Observers say it is difficult to verify the hackers' origins as the IP addresses can be disguised.

Cyber security has become an increasingly prominent issue as security threats in a peaceful era, and seems another way for Western powers to apply pressure to contain China's rise, they say.

Wen Weiping, a professor at the School of Software and Microelectronics at Peking University, put forward his explanation on the belligerence.

The US believes it is justified to launch military attacks on any country that launches cyber attacks threatening its cyber space, he said, and it must raise a fuss against such alleged attacks to build up a case. Wen said the US also aims to strengthen its cyber security forces as a deterrent and maintain its advantage during the information war.

"What is black is black, and what is white stays white. Anyone who tries to fabricate or piece together a sensational story to serve a political motive will not be able to blacken the name of others nor whitewash themselves," foreign minister Yang said.

China, a frequent target of cyber attacks, supports international regulations under the United Nations to keep the Internet peaceful, free and secure, he said, saying the relevant parties should stop irresponsible attacks and accusations against China.

"The international community is closely connected through the Internet, therefore cyberspace needs rules and cooperation, not war."

The effort to formulate a worldwide policy for a more regulated Internet failed in Dubai last December after many Western countries said a compromise plan gave too much power to the United Nations.