Among those detained was Garry Kasparov, the former world chess champion and a leader of Other Russia. The opposition political bloc, which is critical of the government of Russian President Vladimir Putin, says it is using peaceful pressure in an attempt to persuade the authorities to hold free and fair elections next year.
Police and OMON special forces moved to break up the unauthorized rally before it began, but their detention of Kasparov looks certain to provide publicity for Russian opposition efforts.
Police Pull No Punches
MORE: Coverage in Russian from RFE/RL's Russian Service.
Many of those detained went quietly, but others struggled and were forced into police vehicles by officers holding truncheons around the detainees' necks.
Witnesses say Kasparov, who heads the United Civic Front opposition group, was hauled away to a police van, from which the chess whiz was seen waving and smiling to journalists near Pushkin Square in central Moscow.
In Moscow, Dima Tarasenkov of RFE/RL’s Russian Service said police also detained other leaders of the opposition umbrella group Other Russia.
"In Moscow's Pushkin Square, the leader of the youth group of the Yabloko opposition party, Ilya Yashin, was detained, along with another youth leader Maria Gaidar, and several Yabloko activists," he said.
Former Prime Minister Mikhail Kasyanov, another key opposition leader, was blocked by police from entering Pushkin Square.
Police also prevented other key opposition leaders from getting to the square, according to Tarasenkov. "Nikita Belykh, the leader of the Union of Rightist Forces, as well as State Duma Deputy Vladimir Ryzkov tried to reach Pushkin Square but couldn't get there because the police had blocked it off," he said.
Still, around 1,000 protesters went on to rally about 2 kilometers away in the city's Turgenev Square, where authorities had authorized their gathering.
Other Russia has also called for a protest march in St. Petersburg on April 15.
In recent months, three previous demonstrations -- all called March of Dissent rallies -- were either broken up harshly or smothered by police in Moscow, St. Petersburg, and Nizhny Novgorod.
The rallies come after Boris Berezovsky, a Russian multimillionaire now living in London, said in an interview published on April 14 that he was fomenting a revolution to topple Putin.
Other Russia has disassociated itself from Berezovsky's remarks, but they appeared to have raised the political temperature in Moscow.
Also today in the Russian capital, several other rallies took place with the approval of the authorities.
The largest was a pro-government demonstration near Moscow State University organized by the youth wing of the pro-Kremlin Unified Russia party. Organizers said some 15,000 people attended.
(with material from AP, dpa, Reuters)
Demonstrators in Moscow carry a coffin with a television in it to protest government control over broadcasting (TASS file photo)
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