Tour crash
Riders lie on the ground after the Tour de France pile-up (Twitter)

The opening stage of this year's Tour de France ended with 15 riders injured after a bus got stuck on the finish line.

The bus, which belonged to the Australian team Orica-GreenEdge, became wedged under the bridge which covers the line, prompting organisers to issue a series of chaotic and contradictory instructions.

Riders were first told that the finish line would be moved 3km forward. Then, when the bus was finally dislodged, they were informed that the original line would be used after all.

The uncertainty and anxiety caused by these confused instructions resulted in a mass pile-up which snared half the peloton.

German time-trial champion Tony Martin, a key member of Mark Cavendish's sprint train, lost consciousness twice and could now miss the entire tour, while Spaniard Alberto Contador injured his shoulder.

Cavendish himself managed to avoid the pile-up, however the disruption ruined his chances of winning the opening stage after he was caught in queue.

The Manx rider, who has never worn the tour's famous yellow jersey, said: "What caused the problems was the change to the finish. We were hearing in the radios with 5km to go the finish was in 2km. Then, a kilometre later, it's at the finish.

"It was carnage. I'm lucky I didn't come down."

Every rider was awarded the same finishing time as the winner, German Marcel Kittel - meaning each rider's individual performance was essentially irrelevant.

It is reported that the driver of the Orica GreenEdge bus was explicitly instructed by race officials to drive under the arch, despite the clear height issue.

When the nature of his error became clear, the driver was seen sitting in his stranded vehicle, holding his hands over his eyes.

OricaGreenEdge has been fined for causing the disruption, and an inquiry has been opened into the incident.

Watch events unfold on the YouTube video below.