And in two cases, they almost extinguished the flame, but officials in the end, themselves, put out the flame or turned it very low and put it inside the bus to protect the torch and the torch bearers.

NPR: In Paris, Olympic Torch Inflames Protesters

He said the challenge for them was to make the 204 flames "as low-key as possible", which meant that the equipment for each flame had to be as small as possible, including electrical wiring, the gas supply and a flame detector.

BBC: UK