China's official army newspaper Sunday branded the United States Internet surveillance program exposed by former spy Edward Snowden as "frightening", and accused the U.S. of being a "habitual offender" when it comes to network monitoring.

The People's Liberation Army (PLA) Daily hit out at the U.S. for implying that spying on citizens from other countries was justified, and said that the PRISM monitoring program had probably been used to collect large amounts of data unrelated to anti-terrorism operations.

The remarks about the program are some of the most scathing to appear in China's state-run press following Beijing's refusal to make an official comment.

"U.S. intelligence agencies are 'habitual offenders' with regards to network monitoring and espionage," the article, attributed to the PLA's Foreign Languages Institute, said.

"There is reason to believe U.S. intelligence agencies, while collecting anti-terrorism information online have also 'incidentally' collected a lot of information in other fields."

Under the so-called PRISM program, the U.S. National Security Agency can issue directives to Internet firms like Google or Facebook to gain access to emails, online chats, pictures, files and videos that have been uploaded by foreign users.

"U.S. President Obama has said that PRISM is not directed at U.S. citizens," the article said.

"The implication is that for the purposes of U.S. security, monitoring citizens of other countries is not a problem. This simple, overbearing logic is the frightening aspect of the PRISM program.

"The U.S. government says that PRISM is an anti-terrorism program, and does not involve any other matters. But anyone with intelligence expertise can tell this is "admitting ones guilt by protesting innocence."

China has stayed tight lipped following the revelations from the former U.S. government subcontractor, which included claims of U.S. hacking directed at China and which came amid tensions between Washington and Beijing about online espionage.

On Thursday the foreign ministry gave little insight into Beijing's thinking.

"I have no information to offer," ministry spokeswoman Hua Chunying told a regular briefing.

Snowden, who is in hiding in Hong Kong, has vowed to fight any attempt by the U.S. to extradite him. (AP)