China has accused a U.S. spy agency of hacking a government-funded university with aeronautics and space research programs, in Beijing’s latest effort to hit back at Washington’s complaints of cyberespionage.

The National Security Agency’s Office of Tailored Access Operations carried out the attacks on Northwestern Polytechnical University in Xi’an, China’s National Computer Virus Emergency Response Center said in a statement. A team from the center and 360 Security Technology analyzed the university’s information systems after an attack from overseas was reported in June, the center added.

The NSA conducted more than 10,000 "vicious” cyberattacks on Chinese targets in recent years, collecting more than 140 gigabytes of data of "great value,” it said. The NSA and State Department declined to comment on the allegations.