Tour chaos: protest, tear gas and crashes

France's Julian Alaphilippe has snatched the 16th stage of the Tour de France, his second this year

Tear gas in riders' eyes. A farmers' protest blocking the road. Two key crashes on dangerous descents.

The only thing lacking from the wild 16th stage of the Tour de France on Tuesday was a shake-up in the overall standings.

Frenchman Julian Alaphilippe won the first of three mountainous legs in the Pyrenees, which was briefly interrupted when police used tear gas to disperse a farmers' protest that had blocked the road with bales of hay.

The overall standings were unchanged.

Geraint Thomas in the yellow jersey, second-placed Chris Froome and third-placed Tom Dumoulin all crossed together nearly nine minutes behind.

The farmers' protest occurred 30 kilometres into the 218km leg from Carcassonne to Bagneres-de-Luchon.

Thomas, Froome, world champion Peter Sagan and other riders were treated with eye drops due to the tear gas amid a 15-minute delay.

"I just felt my throat and nose were burning, eyes were burning afterward," Froome said.

"But I think quite a lot of riders were in a similar situation.

It was the latest in a series of incidents involving spectators during this year's race.

"We feel safe. Obviously on some of the climbs not everyone's our fans but we don't feel threatened," Thomas said.

Alaphilippe took the lead when Adam Yates crashed on a technical descent in the finale.

"I knew the finale was tricky," Alaphilippe said.

"I was sad for (Yates) but it could have happened to me, too, because I took a lot of risks. ... I went all out for 220 kilometers today.

"I'm exhausted."

Belgian rider Philippe Gilbert was leading when he crashed earlier in the stage while descending from the Col de Portet-d'Aspet, hitting a wall and flipping off his bike spectacularly but avoiding major injury.

It was the same descent where Italian rider Fabio Casartelli died during the 1995 Tour.

"I thought I was broken everywhere," said Gilbert, a teammate of Alaphilippe's on the Quick-Step team. "But I ended up more or less OK."

However, Quick-Step later announced that Gilbert, a former world champion, was withdrawing from the Tour with a fracture on his left kneecap.

"This isn't how I wanted to finish my Tour and leaving it like this really hurts," Gilbert said.

Alaphilippe also won the 10th stage and is wearing the polka-dot jersey of the mountains classification leader.

Spanish rider Gorka Izaguirre finished second, 15 seconds behind, and Yates crossed third with the same time.

The race remains in the Pyrenees on Wednesday for a 65km leg from Bagneres-de Luchon to Saint-Lary-Soulan Col du Portet that features three gruelling climbs, including an uphill finish - and hardly a stretch of flat road.

"It's going to be massively decisive," Thomas said.

"That last climb is possibly the toughest climb in the Tour ..."