A U.S. intelligence agency gained access to China’s telecommunications network after hacking a university, Chinese state media claimed Thursday.

The U.S. National Security Agency used phishing — a hacking technique where a malicious link is included in an email — to gain access to the government funded Northwestern Polytechnical University, the Global Times alleged, citing an unnamed source.

American hackers stole “core technology data including key network equipment configuration, network management data, and core operational data,” and other files, according to the Global Times.

As part of the NSA’s hack, the agency infiltrated Chinese telecommunications operators so that the U.S. could “control the country’s infrastructure,” the Global Times alleged.

The NSA was not immediately available for comment when contacted by CNBC. The hack has not been verified by CNBC.

The Global Times, citing its unnamed source, reported that more details about the attack on Northwestern Polytechnical University will be released soon.

For several years, China has accused the U.S. of cyberattacks but has not been specific. However, in the last few weeks, Beijing has been more vocal in attributing particular attacks to the U.S., in a ramping up of tensions between the two nations in the cyber sphere.

Conversely, Washington and American cybersecurity firms, have attributed specific attacks to China over the past few years.

The alleged attack on the Northwestern Polytechnical University was first disclosed by China’s National Computer Virus Emergency Response Center earlier this month. The agency also accused the U.S. of engaging in “tens of thousands” of cyberattacks on Chinese targets.

For its part, the U.S. has accused China of massive hacking operations. Federal Bureau of Investigation Director Christopher Wray said in February that China’s cyberattacks have become “more brazen, more damaging, than ever before.”

Wray accused China of trying to steal U.S. information and technology.