China has denied a U.S. newspaper report that computer spies possibly operating in China stole information related to the U.S. Joint Strike Fighter project.

Chinese Foreign Ministry spokeswoman Jiang Yu takes a question at a press briefing in Beijing (file photo)Chinese Foreign Minister spokeswoman Jiang Yu said in a regular briefing Thursday that, "Some people keep making up stories. I don't know what their intention is."

Jiang said China is "resolutely" opposed to so-called cyber crimes and has cracked down on such crimes, including hacking.

She was responding to the latest report on acts of computer espionage originating in China.  

The Wall Street Journal this week said spies used the Internet to break into a computer system containing information about the $300 billion jet project. Current and former government officials told the newspaper that the attack appeared to originate in China.

Officials told the paper that the spies stole a sizable amount of data on the next-generation fighter. But they were not able to access the project's most sensitive information, which is stored on a computer with no Internet access. The newspaper report said computer spies have also been able to infiltrate, or hack, the Air Force's air traffic control system.

Earlier this month, a senior U.S. intelligence official, who requested to remain anonymous, also implicated China in a Wall Street Journal report that claimed spies used the Internet to break into the control systems of the U.S. electrical supply network.

A separate report by researchers at the University of Toronto, published in March, said China appeared to be the base for a large electronic spy network dubbed "GhostNet." The report claimed the network was behind nearly 1,300 attacks on computers in more than 100 countries.

The U.S. Defense Department has not confirmed the reports, but it said China has been pursuing ways to use the Internet for so-called cyber warfare.

Some information for this report was provided by AFP and AP.