Inmates in the U.K. have been organizing deliveries of drugs and electronics via small drones, The Sun reports .

Over the weekend, The Sun reported a drone crash at the Category B Bullingdon jail in Bicester, Oxfordshire. The drone contained large amounts of cannabis, as well as cellphones and chargers. “The drone was in a part of the jail without CCTV,” an insider told The Sun. “It was well-planned. We’ve no idea how many times this method of smuggling has been used before.”

But this crash is just the latest in a string of drone drops–according to the U.K. Ministry of Justice, at least nine drones have attempted to infiltrate prisons in the U.K. in the first half of 2015.

The potential security threat reaches beyond smuggled drugs or luxury items, as drones could also be used to carry guns or other weapons.

For now, the penalty for smuggling illegal supplies into a prison is two years in jail, but parts of the U.K. are calling for more serious consequences. In September, a Prison Service spokesman told the BBC, “We are introducing new legislation to further strengthen our powers, making it illegal to land a drone in prison or to use a drone to drop in psychoactive substances.”