MONTREAL -- A minor from Chambly has been arrested in connection to threats targeting a Longueuil high school that sent it into a preventative lockdown on Friday afternoon that spanned several hours. 

Police placed Heritage Regional High School in the Saint-Hubert borough of the city under lockdown around 4 p.m. on Friday after after the administration contacted them about threats made against students online. 

Students were given the green light to leave at 7:05 p.m., several hours after the lockdown began and about three hours after their classes usually end. 

Without sharing the nature of the threats, Longueuil police said investigators plan to meet with the suspect. 

"The police have assured us that at no point in time was the safety of your children at risk while they were in our building," said the school's principal, Sujata Saha, in a statement. "The police needed to lock the access to and from our school while they conducted their investigation." 

Students and staff were asked to remain inside their individual classrooms until police advised them otherwise -- as they worked to locate the person who made the threats. 

"We're trying to do that as quick as possible," Patrick Barriere of the Longueuil police said while the lockdown was still in effect. 

Given that parents were asked not to go to the school during the lockdown, buses remained on site to take students home when it lifted. 

"They have a protocol to follow, I was told everything inside is going pretty well, kids are being aware of what's going on," Barriere said during the lockdown. "It's a long process, obviously, but it's only for their security to make sure the threat is totally stopped." 

In a statement to parents, Saha said support services are available at the school for students who would like to speak to someone following the lockdown. 

"We know that this caused you and your children great concern," she said. "We will debrief with your children next week." 

Heritage Regional School High was also in a police lockdown in February 2019 due to threats.