Udaltsov, right, gesturing while being escorted from his apartment by masked law enforcement officers on Wednesday as two pensioners look on.
Investigators opened a criminal case Wednesday against opposition leader Sergei Udaltsov and several other activists on suspicion of plotting riots, an apparent escalation in the crackdown on principal figures in the anti-Kremlin protest movement that emerged in December.
Special task force officers in black ski masks arrived at Udaltsov's apartment Wednesday morning to escort him to the Investigative Committee for questioning in connection with the accusations, which are based on a report that aired on a state-controlled television station on Oct. 5.
“Hang in there, make waves to the maximum, they are shutting me away,” Udaltsov said in a text message posted on his Twitter account.
Left Front, the anti-Kremlin organization Udaltsov leads, announced that Udaltsov had been detained for 48 hours, but later Wednesday investigators implied in a statement that he had been released after agreeing to travel restrictions.
The case against Udaltsov follows criminal allegations made against two other prominent figures involved in organizing large-scale opposition protests over the last 10 months: anti-corruption lawyer Alexei Navalny and former State Duma Deputy Gennady Gudkov of A Just Russia.
Navalny faces charges of stealing funds from a state company, and Gudkov was ousted from the Duma last month after being accused of unlawful business activity.
The Moscow protests began in December following parliamentary elections won by the ruling United Russia party amid widespread reports of voting violations and fraud. Protesters have demanded that new elections be held and that President Vladimir Putin resign.
Investigators detained Udaltsov aide Konstantin Lebedev on Wednesday based on the same accusations. Also named as a suspect in the case was Leonid Razvozzhayev, an aide to Just Russia lawmaker Ilya Ponomaryov, who is another active participant in recent street protests.
Udaltsov, Lebedev and Razvozzhayev face up to 10 years in prison if they are charged with and convicted of planning to riot.
Investigators on Wednesday also searched the apartments of the three activists, confiscating electronic data-storage devices, documents and ammunition from a hunting rifle in Lebedev's apartment that investigators said was stored improperly.
As evidence for their claims against the trio, investigators cited hidden-camera footage obtained by NTV reporters and included in the Oct. 5 broadcast of "Anatomy of a Protest 2," the latest mudslinging film by the channel known for attacking Kremlin foes.
NTV said the footage showed the three opposition activists attending a meeting with senior Georgian officials in the Belarussian capital, Minsk, in June. NTV said that during the meeting they received instructions on how to orchestrate riots.
According to the NTV report, one of the officials in the meeting was Givi Targamadze, the former head of the Georgian parliament's defense committee and a close ally of President Mikheil Saakashvili, for whom Russian authorities have shown open disdain.
Countering opposition supporters' arguments, the Investigative Committee denied that footage used in the program had been spliced, pointing to "voice identification" tests conducted by investigators.
Under questioning Wednesday, Udaltsov and Lebedev confirmed that they had met with citizens of Georgia in Minsk in June, but they denied the accusations of planning riots, the Investigative Committee said in a statement.
The criminal case against Udaltsov comes after Duma Deputy Speaker Sergei Zheleznyak requested that a check be run in connection with scenes featured in "Anatomy of a Protest 2."
The film's prequel, aired in March, suggested that protesters at winter opposition rallies had been hired to attend and hinted that the organizers were supported by the United States.
Both videos prompted protests outside the Ostankino television tower, in northern Moscow, where the channel is based.
Udaltsov apparently foresaw that he and other protest leaders would face charges, telling relatives of arrested opposition protesters at a low-profile meeting in July that he had “information from different sources that before autumn, they will put us all behind bars.”
The left-wing politician, known for his fiery speeches at opposition rallies, has flirted with mainstream politics in the past. He campaigned for Communist Party leader Gennady Zyuganov during his presidential bid earlier this year, and some analysts said Udaltsov could replace Zyuganov as head of the party.
Navalny has said on multiple occasions that people have told him he will be arrested and put in jail for his opposition activities.
Navalny has a criminal case pending against him in a Moscow court in connection with allegations that he stole property from timber producer Kirovles during his time as an adviser to Kirov region Governor Nikita Belykh.
“These are old Soviet-style tricks,” Navalny told Interfax on Wednesday, speaking about the case opened against Udaltsov. “The authorities have followed the path of Belarus: repression and imprisonment on various pretexts.”
The West has accused the regime of Belarussian President Alexander Lukashenko of jailing opposition activists without cause.
In June, investigators searched the apartments of Navalny, Udaltsov and another protest leader, Ilya Yashin, as well as that of Yashin's girlfriend, Ksenia Sobchak, the prominent socialite-turned-opposition member. Investigators said the searches were part of an inquiry into a criminal case against activists accused of attacking riot police at a rally on May 6 on Bolotnaya Ploshchad.
Commenting on the charges against Udaltsov, Ponomaryov said the charges appear "completely politically motivated," while Gudkov described investigators' actions as "political intimidation," RIA-Novosti reported.
But Irina Yarovaya, a lawmaker with Kremlin-backed United Russia, said Wednesday's case was just the tip of the iceberg.
"I think plotting mass riots is just the initial assessment,” she said, RIA-Novosti reported. “The conversations that I and the whole country heard bear witness to far more serious crimes."
She may have been referring to alleged discussions in the meeting shown in the NTV report of terrorism plots. The Investigative Committee said it would check the validity of that allegation as well.
Staff writer Alexander Bratersky contributed to this report.