The Tour de France was temporarily stopped after 29 kilometres of stage 16 due to an incident involving protesters.
Police had to intervene when farmers attempted to block the route, with some placing hay bales on the road.
Footage appeared to show a member of the Gendarmes using an unidentified substance, reported by multiple teams to be tear gas, in the direction of the demonstrators.
Several passing riders were inadvertently affected and required treatment from medical personnel.
A statement tweeted by the Tour de France's official account read: "The peloton has been slowed down by protesters. The race is temporarily neutralised."
General classification leader Geraint Thomas and UAE Team Emirates rider Oliviero Troia were among those photographed cleaning their eyes with water.
The race resumed in a neutralised mode just over 10 minutes later.
The riders were free to compete once again after 33km of the 218km stage from Carcassone to Bagneres-de-Luchon.