O’FALLON, Ill. (AP) — A 15-year-old southern Illinois boy is in custody and faces felony charges after authorities say he made threats against an elementary school.

Officials say the teen wrote graffiti on J Emmett Hinchcliffe Sr. Elementary School in O’Fallon, including a threatening message and explicit and vulgar drawings. He is charged with making a terrorist threat, attempt of making a terrorist threat, disorderly conduct and criminal defacement of property.

St. Clair County State’s Attorney Brendan Kelly on Wednesday called it “a serious, serious threat.” Police say the teen appeared in juvenile court and was sent to juvenile detention center. O’Fallon Police Chief Eric Van Hook said the teen “had no intention” of carrying out the threats.

School officials say the threats panicked the community and students were kept home from school.