A 17-year-old student at Rush City High School in east-central Minnesota has been arrested after he threatened a fellow student and also threatened to shoot up and bomb the school, authorities said Tuesday.

Chisago County sheriff's deputies who were called to the school late Monday morning questioned the Rush City boy and arrested him. He awaits charges.

The incident comes as the nation mourns the shooting deaths Friday of 20 6- and 7-year-old students and six adults at Sandy Hook Elementary School in Newtown, Conn., by a gunman who killed himself at the scene.

Rush City School Superintendent Vern Koepp said in a notice on the district website that a social media rumor indicated that the threats were planned for Tuesday, but administrators have concluded that "no tangible threats to student or staff safety exist."

In the wake of the threats, Koepp added, the district requested that the Sheriff's Office have an officer at the high school Tuesday.

PAUL WALSH