Police detained dozens of nationalist demonstrators in Moscow on November 4 at an antigovernment rally coinciding with celebrations of Russia's National Unity Day holiday.
Organizers of the Russian March said more than 70 demonstrators were detained after gathering in southeastern Moscow for the annual rally, which organizers called off almost as soon as it began after police refused to allow participants to carry banners.
That figure could not immediately be corroborated. But OVD-Info, which monitors crackdowns on demonstrations, said "several dozen" people were detained.
Rally organizers said authorities had granted approval for banners at the demonstration. The city government had given official permission for the rally, and hundreds of participants had gathered for the event at the time police intervened.
Video footage showed one woman being carried off in a stretcher after what a Dozhd TV reporter at the scene described as a scuffle with riot police.
A second Russian March, meanwhile, was held in northwestern Moscow on November 4. There were no immediate reports of violence or detentions at that demonstration.
The standoff between police and demonstrators came at the start of a politically charged weekend in which Russians nationwide are marking National Unity Day.
The holiday, which the Kremlin established more than a decade ago, has replaced Soviet-era celebrations of the Bolshevik Revolution anniversary.
This year's holiday comes three days ahead of the centennial of the 1917 Bolshevik Revolution.
A day before the celebrations, Russian authorities on November 3 said they had detained several backers of a self-exiled Kremlin critic in the Moscow area, claiming they were plotting to trigger riots by attacking government buildings and police during the holiday.
The Federal Security Service (FSB) said the suspects are members of a "conspiratorial cell" of Artpodgotovka (Artillery Bombardment), a movement established by outspoken opposition activist Vyacheslav Maltsev.
Maltsev, who has described himself as a nationalist and anarchist, has said on YouTube that Russia is up for a "revolution" this weekend.
The RBK news agency cited unidentified Interior Ministry source as saying that a spate of additional raids targeting Maltsev's group were carried out in Moscow and the surrounding area on early on November 4.
Russia's state TASS news agency quoted officials as saying that more than 90,000 security personnel will be on duty for some 2,000 Unity Day events across the country.
Nationalists traditionally hold rallies on November 4, while Russians nostalgic for the Soviet Union, such as the Communists, celebrate on November 7.
National Unity Day, which President Vladimir Putin established in 2005, officially honors a Russian victory over Polish forces in 1612.
In a ceremony commemorating the event, Putin on November 4 placed flowers at the Red Square monument to Kuzma Minin and Dmitry Pozharsky, who are credited with leading Russian troops against the Poles.
With reporting by RFE/RL's Russian Service, Dozhd TV, AP, TASS, RIA, Interfax, Kommersant, and echo.msk.ru