The Tour de France's 13th stage went ahead under tightened security on Friday following the deadly attack in Nice which has left at least 84 dead.
Riders observed a minute's silence in tribute to the scores of victims of the Bastille Day attack, which President François Hollande called a terrorist act.
The stage began at 08.05 BST, later than scheduled, after race organisers held a crisis meeting with the prefect of the Ardeche department and the gendarmerie - France's military force tasked with police duties.
Race Director Christian Prudhomme said: "We want this day to be a day of dignity as a tribute to the victims. We asked ourselves [whether the stage should be cancelled] but we think, after agreeing with authorities, that the race must continue."
French Prime Minister Manuel Valls faced boos and calls to resign as he laid a wreath for the 84 people killed in the lorry attack in Nice.
Hours later Mohamed Lahouaiej Bouhlel drove a 19-tonne lorry down the promenade killing 84 people and injuring 200 more.
France's prime minister stated on Sunday he believed the man behind the Nice lorry attack was radicalised "very quickly"