ACT Fire & Rescue crews responded to reports of the fire at 11.48am, on level one of a carpark in Petrie Street.

An Emergency Services Authority spokesman said the car fire was extinguished on arrival and no damage to neighbouring cars was reported.

The cause of the fire is unknown.

"Thermal imaging equipment is now being used to assess the scene for [any] further fire," the spokesman said.

Two fire pumpers, a breathing apparatus van, hydraulic platform and a command officer all attended the scene.