A 16-year-old is facing attempted murder and other charges after prosecutors say he tried to ignite an explosive device in a backpack at his southern Utah high school.

The teen also was charged Monday in juvenile court in St. George with misdemeanor graffiti and abuse of a flag for allegedly cutting up an American flag and spray-painting words including "ISIS" on a wall at a different high school in nearby Hurricane.

The FBI determined the group was not involved. The Deseret News reports the boy remains in juvenile detention pending another court appearance. No explosion resulted and no one was hurt March 5 after the backpack was found emitting smoke in a common area of Pine View High School.

Charging documents say the boy told police that if someone got hurt, he probably wouldn't care.