A fire broke out in the main campsite of Silverstone race circuit where Moto GP fans were staying last night.
The fire was confined to the exaust system of a commercial generator at the race track, where the Moto GP is being held this weekend.
Crews from fire stations in Towcester and Brackley were called to the fire, which was caused by overheating, at about 11pm.
The fire was out by the time the firefighters arrived but they cooled the generator with two jets.
The incident was dealt with in about half an hour.
Campers have reported two thefts from the site since the event started on Thursday.
Two victims had valuables stolen from the pockets of their jeans left in their tent as they slept.
Chief Insp Chris Hiillery, who is responsible for the policing of the event, said: “Roll your valuables up into the bottom of your sleeping bag and sleep with them.”