China accused the United States National Security Agency (NSA) on Tuesday of launching “advanced” cyberattacks during the Asian Winter Games in February, targeting essential industries.

Police in the northeastern city of Harbin said three alleged NSA agents to a wanted list and also accused the University of California and Virginia Tech of being involved in the attacks after carrying out investigations, according to a report by state news agency Xinhua on Tuesday.

The NSA agents were identified by Xinhua as Katheryn A. Wilson, Robert J. Snelling and Stephen W. Johnson.

The three were also found to have “repeatedly carried out cyber attacks on China’s critical information infrastructure and participated in cyber attacks on Huawei and other enterprises.”

It did not specify how the two American universities were involved.

The U.S. Embassy in China did not respond to an emailed request for comment.

China’s foreign ministry later confirmed the attacks and said Beijing had raised its concerns with the United States.

“The U.S. National Security Agency (NSA) launched cyber attacks against important industries such as energy, transportation, water conservancy, communications, and national defence research institutions in Heilongjiang province,” the report said, citing the Harbin city public security bureau.

The U.S. Embassy in China did not immediately respond to an emailed request for comment.

The attacks had “the intention of sabotaging China’s critical information infrastructure, causing social disorder, and stealing important confidential information,” it added.

Xinhua said the NSA operations took place during the Winter Games and were “suspected of activating specific pre-installed backdoors” in Microsoft Windows operating systems on specific devices in Heilongjiang.

According to MSN, Three named individuals “repeatedly carried out cyber attacks on China’s critical information infrastructure and participated in cyber attacks on Huawei and other enterprises”, it added.

The U.S. routinely accuses Chinese state-backed hackers of launching attacks against its critical infrastructure and government bodies.

Last month, Washington announced indictments against a slew of alleged Chinese hackers who targeted the U.S. Defense Intelligence Agency, the U.S. Department of Commerce, and the foreign ministries of Taiwan, South Korea, India, and Indonesia.

Beijing denies all involvement in overseas cyber espionage.

After years of being accused by Western governments of cyberattacks and industrial espionage, in the past two years several Chinese organisations and government organs have accused the United States and its allies of similar behaviour.