DETROIT (AP) — A 19-year-old man was arrested after spending months planning an attack against a U.S. Army site in suburban Detroit on behalf of the Islamic State group, authorities said Wednesday.

Prosecutors said the former member of the Michigan Army National Guard , inspired by Islamic State, spent months plotting an attack on the facility.

A former member of the Michigan Army National Guard has been arrested after he allegedly tried to carry out a plan to conduct a mass shooting at a US military base in Michigan on behalf of the ISIS terrorist organization, the Justice Department said Wednesday.