Authorities say juveniles threw a package of "contraband" over a fence at a state prison in Coldwater in southern Michigan.

The Branch County sheriff's office says an adult brought three juveniles from Eaton Rapids on Thursday night to train them for future deliveries at Lakeland Correctional Center. A statement released Friday didn't describe what was in the package.

The sheriff's office says the juveniles were released to their parents. Charges likely will be filed after deputies found drugs in the car. The prison and state police will investigate the contraband package. It's likely that inmates at Lakeland were aware of the planned delivery.