FOIX, France -- Tacks on the road caused flat tires for about 30 riders during the 14th stage of the Tour de France on Sunday.
Race officials were asking police to investigate.
Race director Jean-Francois Pecheux commended Sky Team for encouraging the pack to not speed ahead or take advantage of the disturbance.
Among those affected was defending champion Cadel Evans. Sky Team's leader is Bradley Wiggins, who has the yellow jersey.
Pecheux said on French TV the search for the culprit would be difficult because thousands of fans were on the roadside at the time.
Stage winner Luis Leon Sanchez and several other breakaway riders were many minutes ahead of the pack. They appeared to be spared the sabotage during the 119-mile stage between Limoux and Foix.