By WCCO-TV Staff

RICHFIELD, Minn. (WCCO) — Students at a private school in Richfield were sent home Tuesday morning due to a bomb threat.

Officials at the Academy of Holy Angels said an unknown person called the school in the early morning and implied that an explosive device was at the school.

School was canceled, and students who had not yet arrived on campus were told not to come. Those who rode buses returned home on one, and students who drove to school were told to drive home.

By 9:30 a.m., four local law enforcement agencies and K-9 units had cleared the building and given the all clear that school was safe.

Officials said a similar threat was made to the Academy of the Holy Angels school in New Jersey, and police do not believe the threat was related to the Richfield school. Richfield police are working with authorities in New Jersey and investigating the incident.

Holy Angels will start classes late on Wednesday.