French Arkéa-Samsic rider Nacer Bouhanni suffered a fractured vertebra in the crash and was taken to a nearby hospital, while Manuel Peñalver of Burgos-BH broke his elbow and required surgery.
Bouhanni is one of the most recongisable cyclists in the peloton, having won six stages at Grand Tours - three stages of the Vuelta a Espana and three at the Giro d'Italia - while he has also been one of the more outspoken and controversial personalities in the sport over the years.
Mirco Maestri (Eolo-Kometa), whose collision with the pedestrian started the pile up, posted a photo of himself on social media sporting bruises and road rash following the crash.
"Sometimes you just have to get up and push harder than ever ... thinking it doesn't hurt," he wrote alongside the photo.
Fans reacted in shock on social media, with some labelling the crash "horrifying" and "insane", while others criticised the clueless pedestrian.
One even suggested "somebody could have died".
