Residents of a downtown highrise were forced to leave their apartments early Monday morning after a fire broke out in the building.

The blaze started at about 3:40 a.m. on the 15th floor of an apartment building at the corner of Lansdowne Avenue and Dupont Street.

Over 80 residents left the building and were housed on TTC buses while firefighters extinguished the blaze, said police. In total, 112 apartments were evacuated.

Police said EMS crews treated several people for smoke inhalation on scene. No one was transported to hospital.

The source of the blaze is not yet known. Toronto Fire is still investigating.