South Korea’s military has been forced to remove over 1,300 surveillance cameras from its bases after learning that they could be used to transmit signals to China, South Korean news agency Yonhap reported.

The cameras, which were supplied by a South Korean company, “were found to be designed to be able to transmit recorded footage externally by connecting to a specific Chinese server,” the outlet reported an unnamed military official as saying.

Korean intelligence agencies discovered the cameras’ Chinese origins in July during an examination of military equipment, the outlet said.