MONTREAL -- Four suspects are in custody following a failed attempt to deliver drugs via drone to a Sherbrooke prison.

The arrests came as part of a joint operation by the Surete du Quebec, Sherbrooke police department, Correctional Services of the Quebec Ministry of Public Security and Transport Canada.

The flying device was spotted at 2 p.m. inside the prison perimeter. A vehicle was pulled over soon after and the occupants were arrested.

According to the SQ, a 41-year-old man and 35-year-old woman were in the vehicle, which was seized.

Two other suspects, aged 38 and 40, were arrested in the Wellington St. area of Sherbrooke.

Police were able to locate and recover the drone. The package it delivered inside the prison grounds was also seized. Police said the package contained hashish.

The four suspects could face drug trafficking and mischief charges.