An exhaustive police search turned up no explosives and many of the schools were reopened by midday. Others suspended classes.
Quebec Public Safety Minister Pierre Moreau said a “group” unknown to police had made the threats in an email sent to school administrators in Quebec and neighboring Ontario province, saying they were opposed to the curriculum.
Quebec police were informed about it overnight, he said.
Both Quebec and Ontario have been gripped by labor strife as they seek to negotiate new collective agreements with teachers.
The bomb threat was likely a hoax, according to Moreau, “but it was taken seriously” by Quebec police who are now jointly investigating with the Royal Canadian Mounted Police.