China on Tuesday accused three alleged employees of the U.S. National Security Agency of carrying out cyberattacks on the Asian Winter Games in February. 

The public security bureau in Harbin, where the games were held, said the purported operatives were involved in the attacks on behalf of the agency’s Office of Tailored Access Operations.

While the Chinese government often accuses the U.S. of hacking, the latest allegations went a step further by naming specific individuals and details about the incidents. China typically does not release technical specifications alongside its accusations of hacking, which raises suspicions about their legitimacy. 

According to China’s National Computer Virus Emergency Response Center, “foreign hostile forces” launched hundreds of thousands of cyberattacks on the games.

The state media outlet Xinhua said the NSA “used multiple affiliated front organizations to purchase IP addresses from various countries and anonymously rented servers located in regions including Europe and Asia.” 

The attacks targeted the games’ registration, arrival and departure management and competition entry platforms, they said. The agency also allegedly targeted critical infrastructure connected to energy, transportation, telecommunications and defense research in Heilongjiang province.

"China has expressed its concerns to the U.S. through various means about its cyberattacks on China's critical infrastructure,” Foreign Ministry spokesperson Lin Jian said during a briefing on Tuesday. “We urge the U.S. to take a responsible attitude on cybersecurity issues, stop launching cyberattacks on China, and stop its groundless smears and attacks on China.”

The NSA did not respond to a request for comment and it is unclear if the three alleged operatives are employed by the government. 

In March, the Department of Justice unsealed indictments of 12 people accused of hacking on behalf of the Chinese government, including employees at the cybersecurity firm i-Soon, the Ministry of Public Security, and alleged members of the Salt Typhoon hacking group.  

Accusations of cyber meddling between Washington and Beijing have ramped up in recent years since the discovery of a campaign to infiltrate critical infrastructure systems in the U.S. The Wall Street Journal reported last week that Chinese officials acknowledged the hacks in a secret meeting with their American counterparts in December. 

Alexander Martin contributed reporting.