Great Britain's four-man bobsleigh team narrowly avoided crashing after driver Lee Johnston was hit by a stone thrown from the crowd during their second run in Salt Lake City.

The Royal Marine commando complained he had been hit in the visor while the GB-II team where hurtling down the track at around 80 miles per hour.

Although GB-II managed to complete the course, Johnston was visibly annoyed when he got out of the bob and Team GB officials immediately protested.

A spokesman for the British Olympic Association told BBC Sport Online: "The British team appealed to bobsleigh officials and after studying video evidence, they accepted that an object had interfered with the British bobsleigh.

"They offered a re-run and GB-II accepted."

The re-run was not as good as the first effort, though, as GB-II slipped to 17th place with a combined time of one minute and 34.38 seconds.

GB-I, driven by Neil Scarisbrick, are in 13th place after their two runs in 1:34.14 - 0.88secs off the lead.

USA-I currently head the standings at 1:33.26, with Switzerland-I and Germany-II both at 1:33.35.

There are another two runs on Saturday to determine the medallists in an event which produced Britain's only podium finish at the last Winter Olympics in Nagano four years ago when GB-I claimed bronze.

Johnston told BBC Radio Five Live: "I was coming out of bend 10 and all I saw was an arm come out in front of the bob and an object come towards me.

"It smacked me right in the middle of the visor, which completely blew my concentration - so much so that I nearly crashed in bend 13, I was off coming out of 14.

"It was something that really scared me."

It emerged a child had thrown a stone onto the track. Both the child and its parents were taken away by the US authorities.