(MAYVILLE) — Mayville Elementary School students were evacuated to the high school auditorium Tuesday morning after a written bomb threat was found in a bathroom by a staff member. Authorities say the note was found at 9:30 a.m. and students were quickly sent to the high school as a precaution. Local police and a MSP K-9 swept the building and students returned to class just before Noon after nothing was found. The threat came after a March 24 incident where a 16-year old student was found with a loaded gun and knives in his backpack at the school. That student was arrested on charges of carrying concealed weapons, carrying weapons with unlawful intent, and having weapons in a school zone. Tuscola County Prosecutor Mark Reene says the boy made a verbal threat to harm another student prior to his arrest. Mayville Community Schools Superintendent Barry Markwart says all threats made against the school or students is taken seriously and investigated. He said in a letter to parents that there will be an increased presence of police in and around the school.