(KAIR)--A “potential threat” led the Atchison County Schools to take precautionary measures Wednesday.

According to a message posted to USD 377’s social media accounts, the Junior-Senior High School was placed in a “controlled environment” Wednesday morning while law enforcement investigated.

Atchison County Sheriff Jack Laurie told MSC News the continuing investigation was launched after a threatening note was found inside a classroom. “We’re looking into the note that was found, and working with the school in trying to figure out a way to narrow it down as far as time frame, and what class to look at, being that there are multiple classes that attend that same room,” Laurie said early Wednesday afternoon.

According to the district’s social media post, the threat was not found to be credible. Laurie clarified that while the way the note was written led investigators to discount any immediate danger, his office takes all such matters seriously. “Every threat we consider to be credible, except as far as being an immediate threat we don’t believe that to be the case,” Laurie said. “When things like that are put on paper, whether it’s not an immediate threat, or a general threat, we have to look into it either way.”

According to Laurie, a teacher was the one who discovered the note Wednesday morning. It’s believed the note had been left in the classroom sometime Tuesday.