– Jean-Francois Pescheux, competitions director of Tour organisers Amaury Sports Organisation
"We don't know who it was. No-one saw anything.
"We've found some of the tacks. They're the kind of tacks you use in mattresses or carpets. They were obviously thrown by a spectator.
"There were around 50 riders together in the front peloton at the top and about 30 of them ended up with punctures. Some of them had three or four nails in their tires.
"We couldn't neutralise it straight away because we didn't know what had happened. Fortunately Sky neutralised the race."
There have been claims of sabotage at the Tour de France today as a result of around 30 punctures caused by tacks on the road. Tour organisers said "they were obviously thrown by a spectator".