A Caledon secondary school and a nearby Walmart were both evacuated on Wednesday after a bomb threat.

Ontario Provincial Police Insp. Mary Louise Kearns says that police were first notified of the threat at Mayfield Secondary School just before noon.

She said that a decision was then made to evacuate the school and search the premises to ensure there were no explosives located inside.

Police were still searching the building at 5 p.m. In a news release issued later in the evening, police confirmed that no explosives were located.

“It is a 250,000 square foot school with approximately 1,900 students so you can imagine this has taken an immense amount of work,” Kearns said.

A number of area roads were closed as a result of the police investigation and parents were asked to pick up their children from nearby James Grieve Public School.

Kearns said that a number of emergency services participate in the response, including Peel Regional Police as the Walmart is located within their jurisdiction.

“Our focus as was the school staff was to make sure the students were safe and they did a tremendous job doing that. I definitely appreciate that patience of the parents and the community,” she said.

The investigation into who called in the bomb threat remains ongoing.