The Democratic National Committee is warning Democrats not to use Huawei or ZTE devices, after the committee learned that one of its associated organizations was thinking of purchasing ZTE phones for members. “It’s very important that party and campaign workers not use ZTE or Huawei devices, even if the price is low or free,” DNC chief security officer Bob Lord wrote in an internal memo, as reported by CNN. Lord said people shouldn’t be using devices from either Chinese company for work or personal use.

The words echo what federal officials have already said about Huawei and ZTE posing possible security threats to the US. In February, CIA, NSA, and FBI chiefs testified in front of a Senate committee that the two companies were beholden to the Chinese government and the devices could become tools for undetected espionage. Both Huawei and ZTE have denied any cybersecurity concerns.

Singled out for their ties to Beijing

These two Chinese companies have been singled out by the US government for their possible ties to Beijing. In 2012, the US House Intelligence Committee named Huawei and fellow Chinese tech company ZTE as serious risks to national security, claiming that their devices could spy on US citizens and send information back to Beijing. Currently, Huawei is under investigation from the Justice Department for potentially violating US sanctions related to Iran.

It’s worth noting that the DNC is likely not working off any new information here, but that organizers may be on high alert for any potential security threats after Russian military officials hacked the committee in 2016. ZTE did not respond to a request for comment.

Update August 9th, 7:25PM ET: Huawei eventually responded with a statement saying the company’s products are secure and trustworthy, without directly referencing the DNC.

“Huawei has a proven history of delivering products that meet the highest security, privacy, and engineering standards in the industry and are certified to sell in the US by the Federal Communications Commission,” a Huawei spokesperson said. “Huawei devices are developed in partnership with well known, trusted US suppliers and industry peers, and follow the same third-party certification processes as our competitors.