Parents are being ensured their kids are safe after a brief lockdown at Sarnia's Northern Collegiate Institute & Vocational School (NCIVS) on Thursday morning.
In an email to Sarnia News Today, the Lambton Kent District School Board (LKDSB) said an unknown individual was discovered inside the school and police were called to remove them.
It said staff and students were not in danger and the lockdown has since been lifted.
The board thanked students for being calm and following safety protocols, and police for their quick response.
The LKDSB said it recognizes that situations involving a lockdown can be unsettling for students, staff and families.
It said school staff will continue to support students who may have questions or require additional support.
Police said a 42-year-old man from Sarnia was arrested without incident and charged with a Criminal Code offence.
