Spectators throw tacks and nails on the road that puncture tires of several riders, but overall leader Bradley Wiggins and Team Sky slow to allow them to catch up.
Tour de France: Bradley Wiggins and other riders face a different tack
Bradley Wiggins enters the final week of the Tour de France on Monday with a lead of two minutes five seconds but is well aware that the sabotage of Sunday's Stage 14 - when tacks on the road caused a litany of punctures in the peloton - showed how vulnerable riders are on the road, where more severe incidences could yet occur.
Jean-Francois Pescheux, the competitions director of Tour organisers Amaury Sports Organisation, confirmed around 30 riders suffered punctures on the climb of Mur de Peguere on the 191 kilometre route from Limoux to Foix.
The defending champion Cadel Evans (BMC Racing) was among those to suffer flat tyres, and the stage was neutralised, initially by Wiggins's Team Sky squad, as the peloton rolled in more than 18 minutes behind stage winner Luis-Leon Sanchez.
Wiggins, who is aiming to become the first British winner of the yellow jersey in Paris on July 22, said: "What can you do? It's something we can't control. There's nothing stopping more of that sort of stuff happening.
"It's sad. Those are the type of things we have to put up with as cyclists. I think people take that for granted sometimes, just how close they can get to us.
"If that happened in a football stadium, or wherever, you'd be arrested ... But we're out there, quite vulnerable at times, very close to the public on climbs.
"We're just the riders at the end of the day and we're there to be shot at, literally. It's quite sad and hopefully that's not going to continue. There's nothing you can do about it. We just have to get on with it."
Pescheux said: "One or two spectators had thrown nails on to the road, we don't know why, but there were around 30 punctures altogether. The nails were mainly thrown on the ground around 200 metres from the summit.
"At the end, some riders ended up with two or three nails in their tyres."
Pecheux said on French TV the search for the culprit would be difficult because thousands of fans were on the roadside at the time.
Sanchez, whose Rabobank team has been decimated by crashes, had been part of an 11-man break which built a 16-minute lead on the peloton well before the end of the 191km stage from Limoux to Foix.
And after counter-attacking the Frenchman Sandy Casar on the 38km descent towards the finish, the Spaniard made a decisive move with just over 11km to race.
Sanchez went on unchallenged to finish 47 seconds ahead of Slovakian Peter Sagan (Liquigas) with the FDJ rider Casar in third and the main peloton, including race leader Wiggins, coming over the finish 18 minutes in arrears.
"I started the day with victory in mind but given the company I was in I knew I'd have to attack from far out to have any chance," said Sanchez, whose team has only four remaining members from the nine starters.
Monday's Stage 15 will take the peloton 159kms from Samatan to Pau on the northern edge of the Pyrenees.
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