Twenty-three people — 18 children and five adults — were sent to hospital after a fire at a Winnipeg daycare.

Although the fire was small, it sent smoke through the ventilation system, forcing 51 people out of the building Wednesday afternoon, according to a release from the City of Winnipeg.

Emergency crews were called just after 2 p.m. to the Elmwood Winter Club on Brazier Street, where firefighters found smoke coming from a furnace vent.

The 41 children and 10 adults who were inside had already left the building and were inside a nearby school.

The  small fire in the furnace room was quickly extinguished and fans were set up to ventilate the building.

After examining the 51 people, 18 children and five adults were sent to hospital for further assessment.

The cause of the fire is under investigation and damage estimates are pending.

Air quality was back to normal and the daycare reopened Thursday.