Authorities in Denmark are urgently studying how to close an apparent security loophole in hundreds of Chinese-made electric buses that enables them to be remotely deactivated.

The investigation comes after transport authorities in Norway, where the Yutong buses are also in service, found that the Chinese supplier had remote access for software updates and diagnostics to the vehicles’ control systems – which could be exploited to affect buses while in transit.

Their investigations found that remote deactivation could be prevented by removing the buses’ sim cards, but they decided against this because it would also disconnect the bus from other systems.