Oskaloosa High School was evacuated Friday morning after a bomb threat was discovered written on a bathroom stall, according to the Jefferson County Sheriff’s Office.

After the threat, school administrators locked the school and moved middle school and high school students and staff in the high school and middle school to an area of the elementary school that had been searched.

Members of the Jefferson County Sheriff’s Department and Kansas Highway Patrol K-9 Units searched the building and found no hazard, according to Kirk Vernon, a detective sergeant with the sheriff’s office. Vernon said video surveillance recordings at the school will be reviewed.

The district used its paging and e-mail system to notify parents. Students returned to class after the school was searched.

Vernon encouraged anyone with information about the threat to call the Oskaloosa school district at 863-2281 or the Jefferson County Sheriff’s Office at 863-2765.