Among those detained on Russia Day, a public holiday, were opposition leader Alexei Navalny, who faces up to 30 days in jail, teenagers and Russian and foreign journalists
Russian authorities sought Wednesday to crush a new protest wave, arresting more than 400 people at a Moscow march, a day after police suddenly dropped trumped-up drugs charges against a respected journalist.
Among those detained on Russia Day, a public holiday, were opposition leader Alexei Navalny, who faces up to 30 days in jail, teenagers and Russian and foreign journalists.
As police beat up the protesters and even detained random passers-by, President Vladimir Putin congratulated the nation, saying he would do everything to promote the country's "further prosperity and development."
Many Russians had hoped to harness the widespread outrage over last week's arrest of respected reporter Ivan Golunov on trumped-up drugs charges to press for genuine reform of Russia's tainted law enforcement and justice systems.
But a much smaller crowd of protesters had turned up in central Moscow amid fierce divisions among liberals.
Police in riot gear moved in against the unsanctioned march at which some protesters chanted anti-Putin slogans.
Police brutally manhandled some protesters and beat others with truncheons amid shouts of "you are criminals" and "stop police terror."
As police dragged protesters into vans the crowd yelled: "Shame, on Russia Day, this is our country's day! Have you forgotten the constitution?"
OVD Info, which tracks arrests, said more than 420 people were detained. Moscow police said earlier around 1,200 took part in the march and more than 200 people were arrested. Some of the demonstrators were later released.
Headache for Putin
The protesters said senior officials behind Golunov's case should be punished and called for broad reform of police and courts.
Many called for the release of victims of police abuse and political prisoners including Ukrainian filmmaker Oleg Sentsov.
Golunov, who investigated corruption at Meduza, an independent Russian-speaking website, was framed in what was seen as punishment for his work.
Two senior policemen are expected to be dismissed.
Golunov's case presents a major headache for Putin who has in recent months been struggling with low approval ratings amid economic trouble and rising poverty.
His arrest sparked a public outcry and triggered unprecedented solidarity among media, with three top newspapers publishing the same front page: "I am/we are Ivan Golunov" in giant letters on Monday.
Wednesday's march was initially called to press for the release of Golunov who was then suddenly freed on the eve of the rally.
Many saw Golunov's release as a Kremlin attempt to avert the new protest wave.
Analyst Andrei Kolesnikov called the lifting of charges against the journalist a sop to critics.
"This does not mean the state is ready to retreat and make concessions," he wrote.
'Contempt for solidarity'
Before Golunov's release 25,000 people had expressed interest in the solidarity march on Facebook.
But in a controversial move, Meduza's top editors and several other journalists urged Muscovites to call off the protest after Golunov's release, triggering a storm of criticism.
A large crowd of Muscovites including a number of prominent Russians turned up regardless.
Some of the protesters wore T-shirts in support of Golunov. One detained activist brandished a placard saying, "I am Ivan Golunov" in the window of a police van.
A number of journalists were detained including a producer for the German news magazine Dr Spiegel.
"The authorities are very much scared of the fantastic and unanimous display of solidarity in the Golunov case," Navalny said on Twitter.
Amnesty International accused the Russian authorities of "contempt for solidarity and rights," saying police arrested even children.