A bomb threat at Concordia University prompted the Montreal-based school to evacuate and close several buildings on March 1.

Three buildings on Concordia’s campus—the Hall Building, the EV Building and the GM Building—were evacuated at 11:30 a.m. due to a threat sent to the school and several media outlets, including the Montreal Gazette.

A letter written by a group called the “Council of Conservative Citizens of Canada” was sent to the Gazette and was published in its entirety on the publication’s website. The letter stated that the group would detonate an explosive device once per day between March 1-3 in the Hall Building and EV Building, where the group claimed Muslim students “hang out.”

The letter said the bombs were “not meant to kill anybody” but were intended to injure Muslim students. It said some of the “male members” of the group had spotted Muslim students using public washrooms on campus to wash their feet and “walking between their prayer space and the men’s room. . . in flip-flops with bare wet feet.”

The group said they would not detonate any bombs if the university banned “Muslim activities.”

A public statement from Concordia’s president, Alan Shepard, said the university contacted police immediately after receiving the threat, and worked closely with authorities “to ensure that our campus is safe and secure and the individuals responsible for the threat are identified and apprehended.”

Classes were cancelled in the affected buildings until 6 p.m.

The Gazette reported that police had found no evidence of bombs in any of the buildings under investigation.