Bourg d'Oisans - A spectator threw a smoke bomb into the Tour de France peloton as it passed by on Friday.
Nobody came to any harm. Unlike on Thursday, when a fan's camera strap appeared to snag Vincenzo Nibali's handlebars on Alpe d'Huez, causing him to slam to the ground and break a vertebra.
These incidents are making teams worried that fans are getting out of hand on the most famous climbs of the Tour.
"The organisers need to think of something, or put up more fences," Paolo Slongo, Nibali's coach with the Bahrain-Merida team, told The Associated Press on Friday.
"There is a problem, and it's getting bigger and bigger. We've got to figure out something to resolve it."
Nibali's accident occurred in a cloud of yellow smoke set off by spectators, with two police motorbikes not much more than a couple bike lengths in front of the stage leaders.
"The Tour de France was scared that something was going to happen to (Chris) Froome in this last climb and that was the reason they were so close to the riders," Bahrain-Merida sports director Rik Verbrugghe said.
"There are a lot of motor bikes in the race and that's something maybe we need to think about in the future."
In the 2016 Tour, Froome had to run up Ventoux when his bike became mangled in a crash that involved two other riders and a police motorbike.
Attitudes toward Froome and his Team Sky soured recently when the four-time Tour champion was involved in an asthma drug case stemming from last year's Spanish Vuelta - even though he was cleared of wrongdoing just days before the Tour started.
Fans have booed and whistled at Froome throughout the race and with the huge numbers of spectators lining the 21 hairpin bends up Alpe d'Huez, Sky discussed security for Froome on the climb with race organisers.
Still, that didn't stop one spectator from placing an aggressive hand on Froome's back in a gesture that the rider did not appreciate.
"Months and months of waiting (for the anti-doping case to end) fuelled the suspicion and it took its toll," said race director Christian Prudhomme, who informed Team Sky that Froome was not welcome at the Tour before he was cleared of doping.
Fans also booed at Geraint Thomas, the Sky rider who became the first cyclist in Tour history to win atop Huez while wearing the yellow jersey.
"As a Frenchman, I'm ashamed," Sky sports director Nicolas Portal said.
Nibali, the 2014 Tour champion, was fourth overall and one of the few riders who appeared capable of challenging Thomas and Froome - who sit 1-2 - for the title.
"He was feeling really good yesterday and he was looking for the stage victory," Slongo said.
Slongo said Nibali will rest for 15 days and look to return for the Spanish Vuelta in August.
Franco Pellizotti, a teammate of Nibali's and the oldest rider in the Tour at 40, noted that incidents with fans on Alpe d'Huez are nothing new - such as when Giuseppe Guerini rode into a spectator taking a photo in the middle of the road in 1999.
Fans camping out on Huez for weeks before the race create a raucous atmosphere.
"It's OK to party but you've also got to respect the riders," Pellizotti said. "It's great for us that all of these fans are there, it really motivates you. But unfortunately sometimes the partying gets excessive and yesterday there were a lot of drunk people.
"It doesn't take much to make a rider fall."