Amazon has asked its employees to delete TikTok from their phone, citing security concerns. Amazon sent an email to its employees on Friday instructing employees to delete the app from any devices which “Access Amazon email.” If they didn’t remove the app, then their device would be cut off from accessing Amazon’s email system. Employees could still view TikTok’s website from a browser on a laptop, so long as they didn’t install the app.

The news was first reported by the New York Times, Motherboard has also seen and verified the email.

Chinese multinational ByteDance Ltd, a company with close ties to the Chinese Communist Party. Use of the app has exploded during the pandemic, which has prompted concerns from users and the U.S. Government. On July 7, U.S. Secretary of State Mike Pompeo said Washington was looking at the possibility of banning the app. Security experts have long been sounding the alarm about the data TikTok collects. ByteDance COO Kevin Mayer has claimed that TikTok doesn’t store user data on mainland China.

Recently, TikTok said it would leave the Hong Kong market in response to political unrest against China. Senior executives have also talked about restructuring itself and moving its headquarters out of Beijing to avoid the perception it’s a tool of the Chinese Communist Party.

"User security is of the utmost importance to TikTok—we are fully committed to respecting the privacy of our users. While Amazon did not communicate to us before sending their email, and we still do not understand their concerns, we welcome a dialogue so we can address any issues they may have and enable their team to continue participating in our community," a TikTok spokesperson said in a statement. "We're proud that tens of millions of Americans turn to TikTok for entertainment, inspiration, and connection, including many of the Amazon employees and contractors who have been on the frontlines of this pandemic."