Officials in Harbin, China, have alleged that the U.S. National Security Agency (NSA) orchestrated a series of advanced cyberattacks during the Asian Winter Games held in February.

As reported by the state news agency Xinhua on Tuesday, authorities have added three alleged NSA operatives to a wanted list. The investigation also implicates the University of California and Virginia Tech in the attacks, although the report stops short of outlining the exact nature of their alleged involvement.

The report didn’t clarify how the two US universities were allegedly connected to the attacks. However, it provided extensive details about the cyber operations and the individuals suspected of carrying them out.

“The U.S. National Security Agency (NSA) launched cyber attacks against important industries such as energy, transportation, water conservancy, communications, and national defense research institutions in Heilongjiang province,” Xinhua reported.

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

The NSA’s cyber operations coincided with the Winter Games and were “suspected of activating specific pre-installed backdoors” in Microsoft Windows systems on targeted machines in Heilongjiang province.

To conceal its activities, the agency allegedly bought IP addresses from different countries and “anonymously” rented a large number of network servers, including infrastructure based in Europe and Asia, the report said.

According to Xinhua, the goal was to harvest personal data from athletes participating in the games. The cyberattacks reportedly intensified beginning Feb. 3, during the first ice hockey match.

Systems connected to the event, including the registration platform, were among those hit, compromising “sensitive information about the identities of relevant personnel of the event,” the outlet reported.

China’s Ministry of Foreign Affairs later acknowledged the attacks, stating that Beijing had formally raised concerns with the U.S. government.

“We urge the U.S. to take a responsible attitude on the issue of cyber security and … stop unprovoked smears and attacks on China,” ministry spokesperson Lin Jian said.