MANISTEE COUNTY, MI -- A 17-year-old Northern Michigan native was arrested this week after police said he threatened to shoot up a high school in Manistee County.

Police arrested the Wellston teen Monday, Feb. 19, for making a terrorist threat -- a felony punishable by up to 20 years in prison. The alleged threat was made verbally last week toward Brethren High School of the Kaleva Norman Dickson School District.

A group of students at the school heard the threat and notified the principal Monday. Deputies from the Manistee County Sheriff's Office made contact with the teen Monday upon being notified.

Police said the teen admitted to making the threat, but said he was "just joking."

Police confiscated the teen's cell phone and an AR-15 from his residence. Manistee County Undersheriff Kenneth Falk said the rifle belongs to the student's parents, who willingly turned it over to police for safekeeping.

The teen was transported to the Manistee County Jail, where he remains in custody pending arraignment. A report has been submitted to the county prosecutor for review.

Falk said he hasn't been informed of any previous encounters between the student and local authorities.

Monday's incident came less than a week after a 19-year-old killed 17 people and injured 14 more when he opened fire inside Marjory Stoneman Douglas High School in Broward County, Florida.