The coronavirus pandemic issue has quieted since the Tour de France left Nice on Saturday, but concerns surfaced after Thursday's sixth stage.

The Col de la Russet was the highlight for spectators on Thursday, with fans flocking to the switchbacks on the steep section around 5km from the summit.

As is customary for fans who climb mountains to watch the Tour, many fans offered encouragement to the riders, much to the dismay of some.

According to the Dutch newspaper AD, "I am pleased with the cheerful people along the way, but it is still a risk on a climb like this," said Tom Dumoulin of Jumbo Visma.

"We saw more people today than in the last few days. Especially in the last few kilometers, there were a lot of enthusiastic spectators without masks, which was disgusting."

"Virologists say the chances of getting infected during a bike race are low, but that doesn't mean it's safe. All it takes is one spectator to get infected with corona and cough it up, and the riders will pick it up." Race organizer ASO is trying to reduce the number of fans on the uphill by banning cars and campers, but spectators can still walk up the hill.

Through the Tour Caravan, the ASO is also conducting an information campaign to encourage people to wear masks and to keep their distance from riders. Although the police enforce regulations, the wearing of masks is only mandatory in the mountainous regions of France, where the infection rate is highest.

Thomas de Gendt (Lot Soudal) also took issue with the large number of fans on Thursday, calling the situation "unsafe."

"The crowd cannot give a push again this year," he said.

"Everything is closed at the finish, but it's a sham. But it is a sham. I smelled beer coming out of someone's mouth, so if that person is infected with coronavirus, the athlete running next to him could be infected too."

Elsewhere, Matteo Trentin made a public appeal on social media: "Dear fans and spectators, if you see us on the road, please wear a mask! The safer we can make the racing environment, the better for all of us. #21]

It is unclear whether Dumoulin, de Gendt, and Trentin have communicated their concerns to the CPA, the union representing professional riders. Earlier this month, Nicolas Roche and Team Sunweb did so after encountering similar problems at the Criterium du Dauphiné, also an ASO race.

"It is important to raise all the issues today so that we can fix them a little before the Tour," Roche said.