* Fog, rain and snow, but skiing events go on
* France and Slovenia claim day's early golds
* Organisers seek to clear medals backlog
* Members of Pussy Riot protest group arrested
* Bidders may have to abide by anti-discrimination rule
By Mike Collett-White
SOCHI, Russia, Feb 18 (Reuters) - Snowboarders and skiers raced through fog and rain at the Winter Olympics on Tuesday as organisers fought to clear a backlog of events in the mountains, while on the Black Sea coast, hosts Russia meet Norway in a do-or-die men's ice hockey clash.
In the first medal to be decided on a wet, misty day, the men's snowboard cross athletes soared over jumps, muscled rivals aside for the inside line and crashed out spectacularly in a thrilling contest narrowly won by Pierre Vaultier of France.
He edged out Russian Nikolay Olyunin in the final at the Rosa Khutor Extreme Park, but not before there had been a delay following an injury to Italian athlete Omar Visintin, who was carried off on a stretcher.
The crash was a reminder of the dangers of competing on the edge, and of how organisers are trying to strike a balance between keeping the Games on track and making them safe.
It was at the skicross venue that Russia's Maria Komissarova broke her back during training on Saturday. She had emergency surgery to attach a metal implant to her spine, and has been flown to Germany to be treated further at a specialist clinic.
The host nation will be desperate to keep events moving as Russia's first Winter Olympics enters the final stretch.
The Games, which by some estimates are the most expensive ever staged, is a source of great pride to Russia and its president, Vladimir Putin, especially after vocal criticism over Russia's human rights, spiralling costs and corruption.
The International Olympic Committee said on Tuesday that future bidders may have to abide by a specific anti-discrimination rule modelled on the Olympic Charter's Principle 6 if they are to be awarded the Games.
Principle 6 says sport does not discriminate on any grounds, including race, religion, politics or gender.
The IOC had to fend off criticism in the run-up to Sochi over Russia's anti-gay propaganda law, which critics say curtails the rights of homosexuals in the country.
There has been little sign of dissent against legislation introduced last year, although in the most prominent act of protest so far, two members of protest group Pussy Riot were detained by law enforcement authorities on Tuesday.
Maria Alyokhina, one of the two held, said on Twitter that they had been detained on suspicion of committing a crime, but did not give details.
But protests have been largely forgotten as thrills and spills on ice and snow have captured the world's imagination.
Putin has been a regular presence at venues in Sochi on the coast and up in the Caucasus Mountains, in a bid to project a more friendly, open face to the West, with which he has often clashed over issues ranging from Syria to Edward Snowden.
MAZE CLAIMS SECOND TITLE
On the 11th day of full competition at the Feb. 7-23 Games, favourite Tina Maze won her second gold of the Sochi Games in the women's giant slalom.
The Slovenian, who shared downhill gold with Swiss Dominique Gisin in an Olympic first, made the most of starting first in slippery conditions to comfortably lead after the first run.
But it came down to hundredths of seconds in the end, as she just edged out Anna Fenninger of Austria.
Ninety skiers were on the start list for a race that traditionally includes athletes from many non-Alpine nations.
Among those making up the numbers was violin virtuoso Vanessa Mae representing Thailand. Racing under the name Vanessa Vanakorn, she finished 26.98 seconds behind the leader after the first descent.
"I nearly crashed three times, but I made it down and that was the main thing," the violinist, who took a wide berth round most of the gates, told reporters.
"Just the experience of being here is amazing. I was worried I was going to get lost (on the track), but I managed it."
ICE HOCKEY PLAYOFFS
For most Russians, the big contest of the day comes at the futuristic Bolshoy Ice Dome, where the hosts face Norway in a mid-afternoon qualification playoff.
Russian players have sought to reassure the passionate home support, despite not qualifying automatically for the quarter finals of a competition Russians would love to win more than any other.
"In principle, it makes no difference," said Russia's Alex Ovechkin of the extra game. "Each team is now in the peak of its form. Of course, we'd want to play one match less, but this way we'll stay in good form."
Canada and the United States are fancied above Russia, but a gold for the host nation in a final being played just hours before the closing ceremony on Sunday would provide the fairytale end to the Sochi Games.
Russia lie second in the overall medals table behind Germany, although their five golds are matched by the Netherlands, United States, Norway, Switzerland and Belarus.
In the women's ice hockey contest, the two superpowers of the sport - Canada and the United States - will meet, as predicted, in Thursday's final.
In other medal events on Tuesday, Dutch speed skater Sven Kramer seeks to add the 10,000 metres title to his 5,000 gold and extend the remarkable run of success the Netherlands have enjoyed at the Adler Arena.
The United States, meanwhile, are still seeking their first speed skating medal after an embarrassing switch of suits midway through the Olympics.
The weather has stalled Frenchman Martin Fourcade's bid to win a third Sochi gold, twice forcing the postponement of the men's 15km mass start. They will try again on Tuesday. (Editing by Peter Rutherford)