Five people were injured, none seriously, on Saturday in a fire that sent flames bursting out of windows from a residence on the 50th floor of the Chicago's famous John Hancock Center, according to the Chicago Fire Department.

The fire broke out on the east side of the 100-story building in mid-afternoon and was quickly extinguished by responding firefighters, according to tweets by the Chicago Fire Department.

The fire began in a bedroom and spread through the rest of the apartment, gutting it, the department said. The cause of the fire, confined to the one apartment, is under investigation but was determined to be accidental.

Five people suffered smoke inhalation or other minor injuries and were in good or stable condition, the department said. Several ambulances responded to the scene.

The fire department posted pictures of the flames coming from the building as smoke obscured views of the upper floors.

The Hancock building, a landmark in downtown Chicago, has condominiums on most of the upper half floors and an observatory popular with tourists for its sweeping views of the city and Lake Michigan.