The race continues on Sunday, with a 222.5km-eighth stage from Colmar to Pontarlier, but Armstrong's team will be without American rider, Christian Vandevelde.

Vandevelde crashed out midway through the stage, was taken to hospital for x-rays and will play no further part in the team's bid to win Armstrong a third straight Tour win.

"It's definitely not a good time to lose Vandevelde," said US Postal's sporting director Johan Bruyneel.

"To lose anyone is a problem but we were counting on him to be the man there until the climbers have to come in."

Italian team Fassa Bortolo lost its second rider after Ivan Basso was forced to pull out with a stress fracture to his collarbone.

Basso was in a group of five riders who escaped the main peloton and was 10km from the finish when he fell on the descent of the Collet du Linge.

The 23-year-old Italian, who was world junior champion in 1998, remounted and finished fifth in the stage.

That would have taken him into contention in the overall standings but his team confirmed later that he would be taking no further part in the race.

He follows team-mate Francesco Casagrande who abandoned the race on Wednesday.

Four non-riders hospitalised

There was far worse news after the stage finished when four people were injured after an "insane" cycling fan deliberately rammed his vehicle through the crowded finish line.

The driver's vehicle threw metal barriers into the air, causing panic at the end of the Tour's seventh stage, officials and witnesses said.

One woman injured in the incident suffered two broken legs and lost consciousness, police said.

All four victims, including two police officers, were taken to a hospital in Colmar.

Police said the driver of the car had been arrested and was being questioned. His identity was not released.

Tour director Jean-Marie Leblanc expressed sympathy for the victims of the incident, which came despite new security measures in place this year.

"We have worked very thoroughly on all safety measures in cooperation with the police (but) nobody can be prepared for such an insane person forcing his way through the barricades," Leblanc said in a statement.