Schools around Roscommon County were placed into secure mode Tuesday afternoon after a threatening call to a local business.

The Roscommon County Sheriff’s Office says the business owner notified police that the caller had threatened a “mass casualty event” at an unspecified school. Schools around the county were placed in secure mode and law enforcement agencies were dispatched to secure the schools outside. Investigators believed the call to be an instance of “swatting” where a false threat is made to provoke an emergency response.

The call was tracked down to Harford County Maryland, where sheriff’s deputies spoke with a 29-year-old male suspect. Officials say the suspect confessed to making the phone call, but he had no way of carrying out an attack in Michigan. The sheriff’s office says there may still be an increased law enforcement presence at schools this week as an added precaution.