Russian police have detained three opposition leaders during an unauthorized demonstration in the center of Moscow.
Correspondents on the scene reported that policemen surrounded Aleksei Navalny and Ilya Yashin on Pokrovka Street and forced them into a police vehicle.
Left Front leader Sergei Udaltsov reported earlier on his Twitter account that he also had been detained.
"What are these people doing? They are not holding any placards, they just approached Udaltsov," Udaltsov's lawyer Violeta Volkova told Reuters after Udaltsov was detained.
"Is it prohibited? Do we have a law prohibiting more than three people to gather? I think that he [Udaltsov] was detained illegally."
Moscow police say that all three detained leaders will face administrative charges for violating public order.
The opposition rally by some 200 people on October 27 was in support of arrested activists including Leonid Razvozzhayev, who claims to have been kidnapped from Ukraine and forcibly brought to a Moscow jail earlier this week.
The rally began near the headquarters of Russia's Federal Security Service (FSB), where protesters displayed banners declaring, "I am against torture and repression."
The protesters then spread out, apparently trying to make use of a Russian law that says a person can protest alone without any permission from the authorities.
Razvozzhayev Says Kidnapped
The banners carried by the protesters referred to Razvozzhayev's claim he was tortured after he was abducted by unidentified men in Kyiv, where he was applying to the UN for asylum.
Razvozzhayev told human rights leaders who visited him in detention in Moscow that he was forced by his abductors to sign a confession that he had plotted mass riots. His lawyer says he has since disavowed his confession.
Investigators earlier this week said that Razvozzhayev had turned himself into police in Moscow and confessed voluntarily.
Razvozzhayev, along with Udaltsov and Udaltsov's assistant Konstantin Lebedev, were charged this month with plotting mass riots after a documentary aired on a pro-Kremlin television channel claimed the trio want to overthrow President Vladimir Putin.
Meanwhile, members of a number of Ukrainian nongovernmental organizations on October 27 picketed the building of the Ukrainian Security Service in Kyiv.
The demonstrators demanded that the circumstances of Razvozzhayev's departure from Ukraine be clarified.
They also demanded that the chiefs of the Security Service and the Border Service be suspended until the country's leadership explains what happened.
Prokhorov Leaves Business For Politics
In other news, Russian billionaire Mikhail Prokhorov, who finished third in Russia's presidential election in March, said he's leaving business to focus full-time on politics.
The 47-year-old Prokhorov, believed to be worth about $13 billion, told reporters at a congress of his Civil Platform party in Moscow that he has signed a trust agreement under which the partners of his investment group ONEXIM will manage his assets.
He said that he wanted to lead "a third power" in Russia that will compete both with the Kremlin and the opposition.
Prokhorov competed in Russia's presidential election amid speculation that his candidacy was orchestrated by the Kremlin, a charge he denied.
His return to politics comes after he has remained silent during the past five months of the Kremlin's crackdown on the opposition.
With reporting by Reuters, AP, AFP, Interfax, and ITAR-TASS