The investigation has been transferred to the Montreal police's arson squad.

A similar incident took place around 24 hours prior on Monday morning, but that fire caused only minor damage.

No one was injured in either incident.

About 100 firefighters are on site battling a blaze in an apartment building in downtown Montreal. 

Officials are asking commuters to avoid the intersection. 

The man died in hospital, while two women, aged 37 and 62, both suffered non-life-threatening injuries, according to police.

The fire reportedly first broke out on the terrace of a fifth-floor apartment in a Montreal apartment building, located on Doctor Penfield and Atwater avenues.

It is estimated that the school sustained millions in damage from the fire.

Montreal's fire department believes the fire in the four-storey building began in the kitchen of a floor-level unit. 

The fire began just before 6 p.m. on Sunday at a commercial building on Ward Street near Alexis-Nihon Boulevard, according to police.