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 drug charges against a respected journalist.
Among those detained on Russia Day, a public holiday, were teenagers and Russian and foreign journalists.
Opposition leader Alexei Navalny was also arrested but was then released hours later.
Police were seen beating protesters and detaining some passers-by. At the same time, President Vladimir Putin congratulated the nation for the holiday, saying he would do everything to promote the country's "further prosperity and development".
Russians, speaking on social media, said they had hoped for a big protest to harness widespread outrage over last week's arrest of investigative reporter Ivan Golunov and press for genuine reform of Russia's tainted law enforcement and justice systems.
But a much smaller crowd of protesters turned up in central Moscow after Golunov was released Tuesday and the charges dropped, amid fierce divisions among liberals.
Police in riot gear moved against the unsanctioned rally in an attempt to prevent the protesters -- some of whom shouted anti-Putin slogans -- from marching on the Moscow police headquarters.
Police roughly manhandled some people and beat others with truncheons amid shouts from the crowd of "you are criminals" and "stop police terror".
As police dragged demonstrators 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 -- which usually plays down turnouts at opposition rallies -- said around 1,200 people took part in the march and more than 200 were arrested.
Many of the people 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-language website, was widely seen to have been framed as punishment for his work.
Two senior policemen are expected to be dismissed after Interior Minister Vladimir Kolokoltsev on Tuesday said he was asking Putin for their scalps.
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 headline Monday: "I am/we are Ivan Golunov."
Analyst Andrei Kolesnikov called the lifting of charges against Golunov a ploy to deflate protest momentum.
"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. Some accused Meduza of wasting the rare opportunity to press for change.
The crowd of Muscovites that did turn up included a number of prominent Russians, among them authors, directors and doctors.
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.
"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".
- 'Haven't won the war' -
Many protesters said the journalist's case had struck a nerve because nearly everyone could find himself in his place.
"What happened to Ivan Golunov happens every day all across the country. A lot of drug cases happen like this," said 15-year-old Yegor, who wore an "I am Golunov" T-shirt.
"We were lucky that Ivan was freed but it was a small victory -- we haven't won the war."
In the second city of Saint Petersburg, around 100 people gathered, urging authorities to release respected historian Yury Dmitriyev and others.
After Golunov's release many said they would not march and some expressed anger over divisions, saying the authorities had once again managed to split dissenting Russians.
During his two decades in power, Putin has silenced most of his critics.
Rights activists accuse authorities of routinely using trumped-up drug or extremism charges to silence dissenters with jail sentences.