Firefighters in Thunder Bay, Ont., were kept busy with three blazes early Wednesday morning on the city's south side, which fire officials suspect were deliberately set.

The fires all burned garages, sheds and in one case, a child's playhouse, Thunder Bay Fire Rescue stated in a written release issued Wednesday morning.

The first fire was called in shortly after 1 a.m., Wednesday, when firefighters battled a shed fire on Brodie Street S. A garden shed near a laneway was engulfed in flames. Firefighters put the fire out but the structure, as well as a nearby fence, suffered damage.

The next call came in around 2:30 a.m., to an address on Archibald Street S., near the first blaze, fire officials said, and involved a child's playhouse as well as a garage on a neighbouring property.  Both homes were evacuated as a precaution, according to the fire department.

Thunder Bay fire

Fire officials in Thunder Bay say they suspect the three fires may have been deliberately set. (Mary-Jean Cormier / CBC)

One of the homes suffered some heat damage while the outbuildings suffered extensive damage, fire officials said.

Finally, shortly after 3 a.m., while fire crews were battling the Archibald Street blaze, another fire was called in on the same street by city police, Thunder Bay Fire Rescue said.

A large garage was fully engulfed in flames, according to fire officials. The garage sustained heavy damage but no other nearby structures were reportedly affected.

Fire officials said that "due to the timeframe and close proximity of these fires, the Thunder Bay fire investigators are investigating vandalism or possible arson."

The fire service also reminded residents to secure all sheds and garages while keeping properties clear of combustibles or debris.