Authorities say Tuesday night's first fire started when someone left food on the stove unattended. (CBC)Two people were injured and several more are homeless after a pair of fires — one of them suspicious — ravaged two Montreal buildings Tuesday night.

The first fire hit a three-storey residential building on Notre-Dame and Pierre-Bernard streets just after 6 p.m. in the Hochelaga-Maisonneuve district.

More than 150 firefighters were called to the scene.

Two people were sent to hospital for smoke inhalation, but are recovering, the fire department said.

The fire is believed to have started after somebody left food cooking on the stove unattended.

The second fire, which authorities consider suspicious, started around 11 p.m. in a building under construction in the Plateau Mont-Royal district.

Several people neighbouring the building called 911 after hearing an explosion near Pauline-Julien Street.

More than 100 firefighters were called to the scene and neighbouring buildings were evacuated as a precaution.

No one was hurt in the fire.