Police are hunting two teenagers after Tour de France riders Oscar Freire of Spain and New Zealand's Julian Dean were shot and slightly injured during Friday's stage, officials said on Saturday.
"This is the work of a pistol or an air gun," Colmar prosecutor Pascal Schulz told a news conference.
"According to one of the riders, [the shots] would have been the work of two youths aged between 16 and 17 who were hiding behind a tree."
Freire, from the Rabobank team, was hit in the right thigh by a small shot during the 13th stage from Vittel to Colmar but the injury did not hamper him.
Dean, part of the Garmin team, was hit on the index finger.
Both riders started Saturday's 199-km stage to Besancon.
An investigation had been opened into a possible crime of voluntary violence with a firearm -- an offence that carries a three-year prison sentence and a fine of 45,000 euros, officials said.