Richie Porte and Geraint Thomas out of Tour de France after stage nine crashes

One of the pre-race favourites Richie Porte and Team Sky's Geraint Thomas are out of the Tour de France after both crashed during a brutal stage nine on Sunday.

Porte had to be taken to hospital after he was involved in a horrific crash on a treacherous descent during the closing stages of the 181.5km stage from Nantua to Chambery.

BMC later confirmed he suffered fractured collarbone and pelvis as a result of the crash.

"Normally a fractured clavicle (collarbone) and pelvis would require four to six weeks' recovery, providing there are no complications," team doctor Max Testa said in a statement.

Thomas had already been forced to abandon, having gone down earlier on the slippery descent from the Col de la Biche, where he too suffered a broken collarbone.

The Brit had won the opening stage of the race last week and lay second overall going into Sunday's stage, 12 seconds behind Sky team-mate Chris Froome.

Porte began the day in fifth place and looked set to remain in contention, as he was with the group of general classification contenders cresting the day's final big climb, only to slip off the tarmac and onto a grass verge on the inside of a rapid descent.

He then careered across the road, clattering into Ireland's Dan Martin, and the pair crashed into the hard rocky wall at the side of the road.

Martin was able to continue, even after crashing again on the descent, but Porte was given immediate medical assistance by an ambulance and some minutes later he still hadn't moved.

He was subsequently taken to hospital but organisers reported that he was conscious and speaking.

Thomas suffered his fourth crash of the race on Sunday and was forced to abandon as well, having suffered a similar fate at the Giro d'Italia earlier this year, when a crash caused by a police bike, also on stage nine, caused injuries which ultimately forced him to withdraw a few days later.

Reflecting on this crash, he said: "I let (Rafal) Majka in and then he came down right in front of me on a straight bit of road. I had nowhere to go, went over the top of him, and landed on my collarbone.

"Team doctor Jimmy (Juan Mercadel) said he thought it was broken but I got back on the bike and carried on down the descent.

"When I got on the flat, I knew something was wrong. Then the race doctor said exactly the same, so I ended up stopping, went for a scan, and it's broken."

The 31-year-old spent four days in the yellow jersey at the start of the Tour, following his brilliant win in the opening time trial in Dusseldorf, but will not be taking much consolation from his exploits.

"I can't really think about that at the moment," he added. "I'm just thinking of the devastation of leaving the Tour and another Grand Tour.

"I crashed at the Giro on stage nine, and it's stage nine again here. I was lying second overall on both days as well. It's just so disappointing."

After several days of blazing heat on the Tour, patches of rain arrived on Sunday to make the descents on the mountainous 181.5km ninth stage notably treacherous, with Thomas one of several riders to fall in the early going.

Three hors categorie climbs were tackled in total on a brutal day of racing through the Jura mountains, which ended with Froome losing a key team mate in Thomas and also seeing one of his main rivals for overall victory forced out of the race.

Porte and Thomas join a list of star names to have left this year's Tour before Monday's first rest day, following Mark Cavendish, Alejandro Valverde and Peter Sagan - who was disqualified - out of the race.