May 19, 2014 -- Five Chinese military officers were indicted by the U.S. today and charged with hacking U.S. companies to steal industry secrets about nuclear and solar power in what one official called "21st century burglary."

It's the first time ever that the U.S. government has formally accused another nation of using the internet to break into U.S. businesses and shortly after the indictment was announced China suspended the China-U.S. Cyber Working Group.

The most serious charge of economic espionage includes a maximum 15 year prison sentence, although it is unlikely that China would arrest the suspects and send them to the U.S. for trial.

The five officers are members of China's Peoples' Liberation Army and they are accused of hacking into Westinghouse, subsidiaries of SolarWorld AG, Alcoa, U.S. Steel Corp. and other companies between 2006 and 2014. The secrets they allegedly filched were related to nuclear power, solar and metals industries.

The charges were filed in the Western District of Pennsylvania where U.S. Attorney David Hickton said, “This 21st century burglary has to stop."

John Carlin, assistant attorney general for national security, said, “State actors engaged in cyber espionage for economic advantage are not immune from the law just because they hack under the shadow of their country’s flag.”

U.S. intelligence officials have long believed that the Chinese government has been engaged in a state-sponsored campaign to hack U.S. interests and steal research and development. U.S. officials insist such efforts affect national security.

China's Foreign Ministry spokesman Qin Gang released a statement charging that the indictment was based on "fabricated facts" and warned that it "jeopardizes China-US cooperation and mutual trust."

The spokesman was apparently alluding to revelations of NSA cyber sleuthing when he added, "It is a fact known to all that relevant U.S. institutions have long been involved in large-scale and organized cyber theft as well as wiretapping and surveillance activities against foreign political leaders, companies and individuals. China is a victim of severe U.S. cyber theft, wiretapping and surveillance activities."