Two young men appeared in federal court after FBI raids in the Detroit area uncovered an alleged plan for a Halloween terrorist attack inspired by ISIS, though officials say no concrete plot had been formed.

Two men were arrested by the FBI on Tuesday morning in connection with an explosion that went off in Harvard Medical School over the weekend. The pair, Logan David Patterson, 18, and Dominick Frank Cardoza, 20, face charges of conspiracy to damage by means of fire or an explosive, per the charging document.

The arrests followed FBI activity Friday morning in Dearborn and Inkster, spokesman Jordan Hall told The Detroit News.

In a social media post​, FBI Director Kash Patel said multiple suspects who were allegedly plotting a violent attack were arrested in Michigan.

A county sheriff in Mississippi says the FBI has arrested one of his deputies and made other arrests across multiple law enforcement agencies in the state

Buenos Aires was arrested over the weekend by Argentina's Federal Police after the FBI alerted authorities to his social media posts