UPDATE 10:30 a.m.
The Aitkin County Sheriff's Office released a statement updating the situation.
"The incident is under investigation by the Aitkin County Sheriff’s Office, the Hill City Police Department and the Minnesota Bureau of Criminal Apprehension. More information will be made available when it is appropriate.
"There is an increased law enforcement presence in Hill City during this time."
Hill City High School in northern Minnesota cancelled classes Thursday after threats aimed at students were posted to social media.
Hill City schools made the announcement on Facebook:
"School will be cancelled in Hill City today - Thursday February 22nd. Threats have been sent through social media directed at some Hill City students. Law enforcement has been notified and is in the process of an investigation. Students safety is the school districts top priority."
Hill City Chief of Police Josh Kimball told GoMN that it's a "rapidly evolving situation" but couldn't offer any more details about the situation.
Meanwhile, in a strange coincidence, another Hill City High School, this one in Kansas, received threats against students late Wednesday night.
Classes there are in session with officers from the Hill City, Kansas Police Department on the school grounds as a precaution.
GoMN contacted the police departments in Hill City, Minnesota, and Hill City, Kansas, and neither department was aware of the other's situation, so they are believed to be unrelated.
Riceville Schools in Iowa (just south of Albert Lea, Minnesota) also cancelled classes Thursday because of threats against students.
One day after Orono lockdown
Orono schools just outside of the Twin Cities went into lockdown for hours on Wednesday after after a threat involving a gun was made. Nobody was injured nor was a gun found, but an arrest was made. More on that story here.