The LaSalle Police Service is investigating a threat made to Sandwich Secondary School.
Graffiti that included the threat to "burn the school down" was discovered in one of the school's washrooms this week.
Officers attended the school Wednesday to work with school officials to identify the person responsible.
Police do not believe there is any continued threat to public safety.
Police are asking the public, staff, or students to come forward with any information regarding this investigation. Anonymous tips can be made to Crime Stoppers at www.catchcrooks.com or by calling 519 258-8477.