French police are hunting for a woman who caused a spectacular crash on the first stage of the Tour de France, bringing down more than 20 riders.

German cyclist Tony Martin was among those injured in the mass pile-up when a fan waving a cardboard sign and gazing at TV cameras stepped onto the road in front of the peloton on Saturday (local time).

Martin hit the deck, with dozens of other riders falling like skittles behind him.

“The Landerneau police are investigating and we haven’t heard back from them yet,” Tour deputy director Pierre-Yves Thouault told Reuters.

“We are going to repeat our calls for fans to behave time and again, through the police on the side of the road and our social network.

“Most of the fans are peaceful but I want to stress that [when] you come see the Tour, you don’t take selfies, you keep your kids close to you.”

Tweet from @mylissafitz

Fans are back on the tour sidelines in 2021 after a year where they were banned, due to the pandemic. Martin, who started the second stage of the famous race heavily bandaged, pleaded on Sunday for them to show more respect to riders.

“This message is for the people who think that the Tour de France is a circus, for the people who risk everything for a selfie with a 50km/h-fast peloton … please respect the riders and the Tour de France,” the German wrote on Instagram.

“Use your head or stay home!”

Israel-Start Up Nation sports manager Rik Verbrugghe said that while riders enjoyed the support of fans, they created an extra stress in the peloton.

“It’s a good thing to have all those fans on the side of the road but it brings extra stress, extra danger,” he said.

“Most of the time the fans make it pretty dangerous because they make the road narrower. But it’s part of the game, that’s what makes cycling so exciting and so beautiful.”

Race organiser ASO has reportedly filed a lawsuit against the unidentified spectator.

Cyril Lemoine, of France, was injured in another of many accidents that marred the Tour’s first stage. Photo: Getty

Dutch rider Mathieu van der Poel won the second stage of the Tour, beating defending champion Tadej Pogacar and his fellow Slovenian Primoz Roglic, who were six seconds behind.

Van der Poel is already a four-time cyclocross world champion and has won one of the five “Monument” road-racing classics at the Tour of Flanders.

He is the grandson of French cycling great Raymond Poulidor, who competed 14 times in the Tour but never managed to wear the yellow jumper. Poulidor died in November 2019 and Van der Poel cried as he regretted that he could not pose with his grandfather with the famed shirt on his shoulders.

“Imagine if he was here how proud he would have been. Unfortunately, he isn’t here anymore to see,” Van der Poel said.

After the mayhem of Saturday’s crash-strewn opener, Sunday’s second stage was mercifully a lot calmer. Australian Simon Clarke, of Team Qhubeka-NextHash, still took a nasty tumble on a descent but recovered to finish the stage.

Ben O’Connor, GC leader for AG2R Citroen, was also caught up in Saturday’s crashes, suffering a deep wound to his right forearm. He battled through on Sunday, although he is now over three minutes down, as is Ineos veteran Richie Porte.

Australian Jack Haig, the Bahrain Victorious general classification leader, finished 10th on the stage. He is sixth overall, 26 seconds behind van der Poel.

-with agencies