MONTREAL -- In an effort to combat the spread of COVID-19, all Montreal-area school board have cancelled classes on Friday.Some school board offices are opened and select activities are still planned to continue as normal.

Thursday, Quebec Premier François Legault called for the cancellation of all gatherings of 250 people or more. For a list of events cancelled or postponed in Montreal, click here.

At many schools, officials say normal operations, like lunches in the cafeteria, would exceed that number. Education Minister Jean-François Roberge insists it is up to schools to modify their schedules to prevent such large congregations of students.

The following school boards have cancelled Friday classes:

English Montreal School Board (EMSB)

Lester B. Pearson School Board (LBPSB)

New Frontiers School Board (NFSB)

Riverside School Board

Sir Wilfrid Laurier School Board (SWLSB)

Commission scolaire Marguerite-Bourgeoys (CSMB)

Commission scolaire Marie-Victorin

Commission scolaire de la Seigneurie-des-Mille-Îles

Commission scolaire de Laval

Commission scolaire de la Pointe-de-l'Île

Commission scolaire de Montreal (CSDM)

Commission scolaire des Affluents

Commission scolaire des Patriotes

The following schools are also closed:

Académie internationale Charles-Lemoyne

Collège Charles-Lemoyne

Collège Notre-Dame

Collège Reine-Marie

Concordia University (until Monday)

McGill University (until Monday)

Peter Hall School

Université de Montréal (classes of more than 250 people)

UQAM (classes of more than 250 people)

Vanguard School

The LBPSB and the EMSB had initially said they would stay open on Friday, but reversed course late in the day Thursday.

"We wish to apologize at the outset of this message for its lateness, but the current situation with regards to COVID-19 is changing rapidly," the LBPSB wrote on its website.

In a directive send to administrators, Roberge said that if any school had a case of the virus, it would have to close for 14 days. Large gatherings, such as those in agoras or sports centres, should be prohibited, he added.

Some Montreal-area private schools have already cancelled classes this week as a preventative measure after students who had recently travelled abroad were tested for the virus.

Quebec currently has 17 cases of COVID-19. All of those people likely contracted the virus abroad, health officials note. However, they warn that the localized transmission of COVID-19 is inevitable. Another 266 people are being investigated for the virus.

Anyone who has travelled abroad and is experiencing symptoms that could be associated with the virus -- fever, coughing, difficulty breathing -- have been asked to call 811.