The US Justice Department and the FBI have seized internet domains linked to two hacking platforms they say Chinese state-sponsored hackers used to target American networks. The operation disrupted platforms known as QScan and QTRouter.

Federal officials say the group, identified as QTFY and linked to Nanjing Xinjiuwei Network Technology Company, targeted the US Senate, NASA, the Federal Reserve and the departments of Justice, Energy and Health and Human Services. Court documents allege the group also worked for China’s Ministry of State Security and the People’s Liberation Army.

The Justice Department later corrected its announcement, saying its court filing showed the group targeted all the named agencies but compromised only some of them. It did not detail what data, if any, was obtained.

A Chinese embassy spokesperson rejected the accusations, accusing the US of using cybersecurity claims to discredit China. The seizures mark another step in the two countries’ running conflict over state-sponsored cyber operations.