The US Air Force combat wing at Kadena Air Base in Japan’s Okinawa Prefecture has banned vehicles made by China’s automaker BYD from the facility over security concerns, Kyodo News reported Monday.

“These vehicles present an unacceptable and unmitigable risk to our personnel and our mission,” Kadena Air Base spokesperson Lieutenant Colonel Alli Stormer told Reuters, in text republished by eletric-vehicles.com.