A threat against Mitchell High School on Monday turned out to be a false alarm, according to authorities.

At approximately 9:40 a.m., the school district received a report of a “threat of violence” against Mitchell High School, according to Mitchell School District Superintendent Joe Graves. Mitchell police were called, and Graves ordered all doors leading to the outside to be locked at Mitchell schools. Officers were also stationed at Mitchell High School.

According to the Mitchell Police Division, a picture of firearms was posted on the internet with the caption “Don’t go to school tomorrow @ MHS.” The adult who saw the post assumed the threat was made toward Mitchell High School.  Police determined the original post was from the Albemarle County Police Department in Virginia. The threat had been investigated and a juvenile was detained, authorities said.

“The investigation, within minutes, confirmed that the threat was actually related to a school in another state and had nothing to do with MHS,” Graves said in an email to The Daily Republic. “Once this was determined, all building lock-downs were lifted and the school day proceeded normally.”

The South Dakota Division of Criminal Investigation assisted with the investigation.