Monitors in Moscow say more than 400 people have been detained in a crackdown on an unsanctioned march in response to the brief arrest of prominent reporter Ivan Golunov.
The case against the reporter, Ivan Golunov, was dramatically dropped by Russia's minister of internal affairs this week, but protesters said they wanted the police officers responsible for his arrest to be prosecuted.
The authorities had hoped freeing Golunov and promising punishment for those who allegedly framed him would appease his supporters' anger, but his colleagues chose to go ahead with a protest on Wednesday, a public holiday in Russian Federation, regardless. After a public outburst of protest, including by three of Russia's most respected newspapers, the case was dropped on Monday for lack of evidence.
Police in Moscow had earlier put the number detained at 200 and said charges could result in 20 days in jail.
The authorities had warned them in advance that the demonstration would be illegal and could pose a risk to public safety.
Hundreds have been detained in Moscow during a protest inspired by baseless drug charges brought against a journalist who investigated high-level corruption.
"We came to show the authorities that we have consolidated, that we are united", said a protester known as Vsevolod, 24.
Another protester named only by Reuters as Ivan, 28, said the freeing of Golunov did not amount to a victory.
Organisers of Wednesday's event had demanded that Moscow city officials negotiate those terms with them during a live broadcast, something officials refused to do.
"It was a tactical move by the authorities to prevent disorder breaking out today".