MONTREAL -- Quebec will make the wearing of masks mandatory in all public indoor spaces in the province as of Saturday, Premier Francois Legault announced Monday.

The province is leaving it up to merchants and owners of other indoor public spaces to enforce the wearing of masks in their establishments; those who don’t apply it could face fines ranging from $400 to $6,000.

Closed public places include restaurants, but Legault noted that customers will obviously be able to take off their face covers to eat.

"We wear a mask when we are on the move. Once seated, and you are two metres from other people, you can take off your mask. However, when you get up to go to the bathroom or leave the restaurant, you are going to put on your mask, '' he said.

The rule will apply to people age 12 and older, with exceptions for people with specific medical conditions.

"We're not going to ask people to walk around with a medical certificate," said Quebec's director of public health Horacio Arruda, specifying that typically it would be people with severe cardiac or respiratory illnesses, adding that it's up to people's judgment. "It's not because you have a bit of asthma that you can't wear a mask." 

The premier reminded people that gatherings of more than 10 people in homes or yards remains prohibited.

Following a number of outbreaks stemming from bars in the Montreal area and beyond in recent days, Health Minister Christian Dube had a special message to bars.

"We'll monitor very closely, especially with bars," saidDube. "If we see bar owners not applying the rules, we will have to act accordingly… but we need to give them the benefit of the doubt."

On Monday, masks became mandatory on public transit across Quebec.

The City of Montreal, among other municipalities, had already been planning to make masks mandatory in public indoor spaces as of July 27.

The Montreal suburb of Cote-St-Luc had already made masks mandatory indoors early last month.

- With files from The Canadian Press

This is a developing story that will be updated.