A 17-year-old youth is in police custody after a brief "hold and secure" situation at John McGregor Secondary School in Chatham.
Police say at around 10:30am, they got a call from someone who said a student was in possession of a weapon.
Within minutes of that call, police located a student with a knife and took him into custody without incident.
The incident is still under investigation and at this point, police have not released information on whether charges are being laid.