The fire marshal was at a Guelph apartment all day Monday, following a fire that broke out in a second-floor unit Sunday afternoon.

Around 1 p.m., flames and smoke poured out of the second floor of 316 Kathleen Street as crews worked to extinguish the fire.

"The fire itself is basically contained to one unit. We have smoke spread throughout the entire second floor," Mike Ross, the Ontario Fire Marshal, said on Monday.

Residents in 19 units have been displaced. Six Red Cross volunteers provided support to those affected.

"We provided rooms and accommodation, so a place to stay for the night, clothing, food if need be for a couple of days," said Chris Allsop, with the Red Cross.

One resident said they have been advised to stay elsewhere because of the fumes.

"It smells horrible. It smells like burnt plastic," said George Mcpolin, an evacuated resident.

Officials still have not determined whether the fire was suspicious or if it was accidental. They also could not give a damage estimate, as they need more time to determine if there is any structural damage to the walls and roof.

With reporting from CTV  Kitchener's Allison Tanner.