The official mouthpiece of China's ruling Communist Party on Monday roundly rejected claims of hacking attacks from China by American media outlets, hinting instead at ulterior motives by the US.

The People's Daily article echoed vehement government rejections last week after The New York Times and Wall Street Journal linked Beijing to cyberattacks and the Washington Post accused Chinese hackers of targeting it.

The reports added to rising concerns about Chinese hacking -- a US congressional report last year said increasingly skilled Chinese state-backed entities were seeking to breach US systems, calling the country "the most threatening actor in cyberspace".

The front page Chinese-language commentary in the People's Daily, which could not be found on its English website, said: "Even those with little understanding of the Internet know that hacking attacks are transnational and concealable.

"IP addresses simply do not constitute sufficient evidence to confirm the origins of hackers," it added.

The paper accused the US of fanning "fear of China" out of self interest, saying that it has invoked national security as a justification for trade protectionism and economic sanctions.

"America keeps labelling China as hackers, simply playing up the rhetoric of the 'China threat' in cyberspace, providing new justification for America's strategy of containing China," it added.

The article repeated the Beijing government's position that China is also a victim of hacking, saying that there were more attacks from US-based IP addresses on Chinese websites in December than from any other country.

Despite this, it said, "China did not draw simple inferences or hasty conclusions about the attack source".

There were attacks from 3,000 foreign IP addresses in the month, it added.

The New York Times reported last week that hackers stole corporate passwords and accessed the personal computers of 53 employees after the newspaper published a report on the family fortune of China's premier Wen Jiabao.

Some security analysts said the media attacks were probably linked to the Beijing authorities, while others argued it was difficult to ascertain whether the attacks stemmed from China or if hackers acted on government orders.

"The Chinese government clearly has the capability of doing this," wrote the founder of a group, Greatfire.org, that monitors Chinese Internet controls, a system termed the Great Firewall.

"Online censorship in China is both massive in scale and sophisticated, meaning that they have to employ very skilled people," he said, using the pseudonym Martin Johnson for security reasons.

Still, finding hard evidence to tie the attacks to the Chinese government was "nearly impossible," said his co-founder "Percy Alpha".

Hackers from China have previously been linked to attacks on US defence giant Lockheed Martin, Google and Coca-Cola. Other reports say Chinese hackers have tried to infiltrate the Pentagon's computers and those of US lawmakers.

Beijing's defence and foreign ministries last week repeatedly rejected any accusations of hacking.

"Cyber-attacks have a transnational and anonymous nature," the defence ministry said in a statement to AFP. "Under such circumstances accusing the Chinese military of launching attacks through the web without irrefutable proof is unprofessional and baseless."