Three passengers and the driver of an Uber have escaped a fire in Canberra's CBD overnight.

At about 1.00am, nearby partygoers noticed a small fire coming from the front of an SUV in a city carpark.

They attempted to stop the vehicle and extinguish the fire which was starting to spread throughout the engine bay.

Despite the best efforts by several Police and bystanders with extinguishers, the fire could not be controlled.

Firefighters arrived at the scene a short time later and extinguished the fire.

There were no reports of injury.