Russian police have broken up a protest by two groups opposed to Beijing's bid to host the 2008 Olympics.
The protests come just hours before the International Olympic Committee is to convene for its final vote on the site.
Six people, including a Frenchman from the international Reporters Without Borders media freedom organisation, have been detained.
About a dozen demonstrators tried to unfurl three banners across from the World Trade Centre on the Moscow River embankment, where the IOC is meeting.
Some two dozen policemen including officers in riot gear overpowered the protesters and after a minute of struggle led six protesters to a waiting bus.
The demonstration was organised by Reporters Without Borders and Russia's Transnational Radical Party.
The detainees included Vincent Brossel, a French representative of Reporters Without Borders, Alexander Levy, a Russian representative of the same group, and two Russians affiliated with the Tibetan Buddhist Centre in Moscow.
Four other protesters tried to approach the conference centre but were stopped and questioned by police and told not to return if they didn't want "problems".
The protesters included John Hocevar of New York and Ann Callaghan, a British citizen, who had both been briefly detained on Thursday for passing out leaflets opposing Beijing's bid.
After being released, the two resumed their campaign outside the IOC's opening ceremony at the Bolshoi Theater, waving at President Vladimir Putin's motorcade as it arrived.
The protesters say China's actions in Tibet should disqualify Beijing from hosting the prestigious event.