Several anonymous messages were sent Wednesday night threatening Knox County Public Schools, according to Kentucky State Police and the school system.
State police were notified of the threat and increased security Thursday to ensure student safety, according to a release.
There has been no evidence that the threat is credible, according to state police, but troopers will maintain a presence at the schools throughout the day.
Superintendent Kelly Sprinkles said the district is working with officials on a full investigation.
“The safety of students and staff is our first concern,” he said in a Facebook post on the Knox County Public Schools page. “We take all threats of this nature seriously. Local and state emergency response officials have been involved since the first telephone message was received. With support from law enforcement, our campuses have been monitored all morning, and no weapons or suspicious packages have been found.”
Classes remained in session Thursday.