MISSOULA, Mont. -

A juvenile inmate at the Missoula County Detention Center allegedly attacked a guard.

According to the Missoula County Sheriff's Office three juvenile males were in the outdoor recreation area at the jail Monday. When they went inside one of them, a 14-year-old, allegedly hit the detention officer in the back of the head with a plastic cup.

The officer was able to stop the attack and detain the inmate.

Missoula County Sheriff's Office Public Information Officer Paige Pavalone said it was part of a plan to escape. The three juveniles came up with the idea last Saturday.