Police say one of the adults is a police officer. No other information about the injured has been released and there was no immediate word on the condition of the 11-year-old boy.
Toronto police spokesman Const. Victor Kwong says officers ran into the west-end building (near Kipling Avenue and Lake Shore Boulevard) and pulled the three children out of the burning apartment.
He says they were called just before 10 a.m. on reports that flames were shooting out of the unit. The fire was reported to be under control as of 11 a.m., but firefighters remained on the scene.
The incident comes just days after a townhouse fire in the city’s east end claimed the life of a 10-year-old boy and left his mother and sister in serious condition.
Toronto police Sgt. Wayne Jackson says several officers received medical attention for smoke inhalation at the scene but he did not give an exact number.
The Ontario Fire Marshal's office is investigating.