Yesterday, China denied that in June it had attempted to access the Pentagon. This is not the first accusation.
Jiang Yu, a foreign ministry spokeswoman, denied the charges.
The Financial Times quoted American officials who said the People's Liberation Army (PLA) was behind the June hack. American officials interviewed clearly thought China was responsible.
The Pentagon network had been taken offline in response to the attacks.
The attack was against an unclassified email network in the Office of the Secretary of Defense.
A month previously, the Department of Defense claimed that the PLA maintains first-strike cyberwarfare units whose arsenals include computer viruses.
Although Jiang denied the charges, just last week, Angela Merkel, Germany's chancellor, accused China of the same type of hacks. Der Spiegel reported that government ministries as well as Merkel's office, had been infected with spyware planted by Chinese hackers.