Twelve people from three apartments of a multi-unit housing complex in Centretown have been displaced from their homes after a two-alarm fire Saturday night.

Fire crews received multiple calls Saturday night reporting a fire at 51 Argyle Ave., near Elgin Street and Highway 417.

The one occupant was treated for minor burns but was not transported to hospital.

The fire began on the balcony of one of the units and spread between the two layers of brick that made up the outside walls of the building, according to Ottawa fire service spokesman Marc Messier.

A carelessly discarded "smoking material" was the cause of the fire, said Messier.

The damage to the fire was contained to three of the building's six apartments and is estimated at $450,000.