A lockdown at a Hamilton high school has been lifted after police say they found no evidence to support threats made to the school on Monday morning.

Hamilton police Supt. Will Mason said they received a 9-1-1 call from Bishop Ryan Catholic Secondary School at around 8 a.m. after two threats were phoned in at the school.

Mason would not disclose the nature or specifics of the threats, aside from saying that it was a “male voice.”

He said officers were on scene “within minutes” and decided to keep students inside their classroom instead of evacuate the building.

“We take these types of threats very seriously, especially in relation to what’s happened in the States recently,” he told reporters from the scene.

Police deemed the school safe and clear, ultimately lifting the lockdown shortly before 12:30 p.m.

No injuries have been reported, but Mason said a couple students reported feeling faint and unwell and were treated by paramedics at the school.

“It’s probably the trauma of the incident, as well as being contained in those close quarters for such a time,” he said.

“We also recognize that this is a traumatic event for a student to go through, even though this threat turned out to be just that – a threat. We recognize that a student locked in a classroom with little information can be a traumatic event.”

The students were eventually escorted out of the school by police officers and reunited with their parents. Classes scheduled for the remainder of the day were cancelled.

Crisis counsellors have been made available for students and staff who wish to talk to someone about the incident.

“It is a methodical process to be able to clear the school and say that it is 100 per cent safe,” Mason said. “We wanted to be able to say that before we start bringing the students out of the school and reuniting them with their parents.”

At the height of the situation, members of the service’s tactical unit went classroom to classroom to ensure the students’ safety.

Students said when they heard the lockdown bell – different from a typical school bell – they knew something was wrong.

“Nobody knew what was happening, so my door wasn’t locked, so I ran out of the class. I ran to my friend’s house,” said one student. “It was just scary overall.”

Many concerned parents flocked to the building after receiving text messages from their children inside, detailing the lockdown and police presence.

“Honestly I’m still scared. It’s scary… It’s too close to home,” said one parent. “Thankfully he’s out, but I think I’d be sick to my stomach if he wasn’t.”

No arrests have been made and that nothing was found in the school to support the threats.

Mason said the “complex and complicated” investigation is far from over.

“We’re definitely looking at a threat and a threat to cause bodily harm, or a threat to cause death,” Mason said. “There’s a potential mischief charge there, but we have to get further into it.”