Parents are receiving a letter from the Avon Maitland District School Board letting them know about a threat received about noon Thursday that lead to a lockdown at Listowel District Secondary School.
Avon Maitland District Superintendent of Schools, Paul Langis, says the lockdown was downgraded to a hold and secure situation just after 1pm, and students were released for regular dismissal.
Nearby Listowel Eastdale, Listowel Central, and St. Mary's Catholic Elementary Schools were also under the hold and secure designation.
Langis says they tried keep parents and the community informed throughout the ordeal with updates on Twitter and Facebook.
Perth County OPP continue to investigate the threat that lead to the lockdown.
With files from Steve Sabourin