Several floors of a southwest Calgary apartment building were evacuated Saturday night after a fire broke out on an upper storey balcony.

Around 9:30 p.m., the Calgary Fire Department responded to several calls regarding visible flames coming off a balcony at the London Tower building in the 8000 block of Horton Road S.W.

Calgary Fire Department Battalion Chief Alistair Tobin said residents in units two floors above and two floors below the fire were evacuated and placed onto city transit buses.

No one was injured and fire crews managed to contain the fire and smoke damage to just one unit.

"The sprinkler system worked perfect so it stopped the fire from entering the building much. The patio or the balcony were quite heavily damaged but the suite was protected by the sprinkler system," Tobin said.

Tobin said residents of six units were not allowed back into their homes last night. Everyone else who was evacuated was permitted to re-enter the building after the fire department completed its air quality monitoring.

The cause of the fire is under investigation.