UPDATE: Police have arrested one man in connection with this case.

Classes at Concordia University resumed at 6 p.m. following an unfounded threat that targeted Muslim students.

Concordia University evacuated multiple buildings in its downtown campus and cancelled daytime classes after receiving the threat.

Police did not find anything suspicious after examining the three buildings, and confirm that the school is secured.

“Everything has been searched. We didn't find any suspicious objects or explosive objects inside of those buildings,” said Benoit Boiselle, spokesperson for the Montreal police.

The evacuation order came after letters were sent threatening to set off bombs at the Hall building on De Maisonneuve Blvd. and the EV building on Ste. Catherine St.

At 12:30 p.m. the school ordered the evacuation of the GM building at the corner of Guy and De Maisonneuve, which is connected to the EV building.

Concordia University President Alan Shepard said he ordered the evacuation as soon as the letters arrived in the morning.

"We realized it early this morning, about the same time you did because it was sent all around," said Shepard, referring to the letters sent to multiple media outlets.

Access to the Guy-Concordia metro station was cut off, but trains were passing through the station normally.

"I don't want to specify what we're doing, but we have increased security as a result," said Shepard.

Higher Education Minister Helene David said a similar letter was also sent to McGill University.

"We are in communication with McGill University as well, which received essentially the same letter but without naming any buildings," said David.

That school did not order an evacuation because the threat was unspecified.

She said the authorities would find those responsible.

"We strongly denounce this kind of threat against a university where everyone works and lives together so well," said David. "These messages are unacceptable. It's criminal."

The case is now being examined by the Major Crimes division of the Montreal police department.

Threats target Muslims

The letter is from a group calling itself the Council of Conservative Citizens of Canada.

It says "Now that President Trump is in office south of the border, things have changed," then lists several complaints about Muslims.

In the United States, the Council of Conservative Citizens is a white supremacist group that believes people of European descent should not integrate or intermarry with people of other ethnic backgrounds.

It is believed to be the largest white nationalist group in the United States.

Higher Education Minister Helene David said it's the first activity in Quebec by the organization.

"We don't know anything about this group. It's the first time we hear about this group," said David.

Shepard said he spoke to the head of the student Muslim association soon after learning of the letter.

"He is very calm, he is well," said Shepard.

Overall he was surprised that someone would single out students of any one nationality or religion at the school.

"We have a very open university with students from 150 nations. I would say Concordia is a very safe university."

The Muslim Students Association issued a news release Wednesday evening, saying the bomb threats were "deeply troubling."

"The MSA unequivocally condemns all acts of violence and discrimination against any individual or group. No faith community should have to live in fear about the safety and well-being of its community members," the statement read, adding that it wants the threat to be investigated as a hate crime.

The threat came during Concordia’s Islamic Awareness Week.

“We're in Montreal, you know? It's the first time that we hear (of something like this) - especially it's a university, you know? It's - it's shocking,” said student Mamdoh Mallouk.

“I think it's a real shame. I think a lot of what's happening in the States probably encouraging this kind of behavior,” added student Jimmy DiMichele.