Parents up in arms against an Ontario school board's move to keep masks on

FILE PHOTO: A view shows snow covered Hamilton after a snowstorm, Ontario, Canada January 17, 2022. REUTERS/Carlos Osorio

TORONTO (Reuters) - As students in Canada's most populous province return to mask-free classes after two years on Monday, one Ontario school board is facing backlash for defying the province's decision to drop masks, potentially setting the stage for a clash on a contentious pandemic issue.

The mask mandate and other pandemic measures have become a lightning rod in Canada for an anti-government movement, sparking a three-week protest in capital Ottawa last month.