A police investigation into an apparent threat prompted a brief lockdown at Guelph Collegiate Vocational Institute (GCVI) on Thursday.
The Upper Grand District School Board told 570 NewsRadio that GCVI was instructed to follow lockdown procedures shortly after 1 p.m.
The lockdown was then lifted about an hour later.
Guelph police said their investigation was spurred by a threat against the high school.
Investigators thoroughly searched GCVI, but say no evidence was discovered. The threat is believed to be unfounded.
Police said their investigation is ongoing.
“The Guelph Police Service recognizes the importance of school safety and how threats of this nature can be difficult for students, staff, and their families,” said a media release. “Police take incidents like this extremely seriously and will continue to work closely with school boards to help identify the individuals responsible and lay the appropriate criminal charges when a suspect is identified.”