More than 200 people showed up outside the headquarters of the FSB security services carrying placards and moving in single file as required by authorities for unauthorised demonstrations.
Hundreds of people gathered in Moscow on Friday to protest against heavy jail terms handed down to young anarchists on "terror" and other charges by a Russian court this week.
More than 200 people showed up outside the headquarters of the FSB security services, according to an AFP journalist, carrying placards and moving in single file as required by authorities for unauthorised demonstrations.
A Russian court imprisoned a group of young anarchists for between six and 18 years on terror and other charges, with critics calling the sentences "monstrous".
A military court in the central city of Penza handed down the verdicts in the case of the so-called "Network" group.
Rights activists and defence lawyers strongly criticised the probe overseen by the FSB, the successor to the KGB, saying the men had been tortured.
All seven denied the charges in court.
"This is a horrible case that was a fabrication from the start," said Marina Artamonova, a 65-year old at Friday's protest. "This is meant to scare young people so they don't assemble and speak their mind."
Another demonstrator, 25-year old Ayten Yakubova, said the verdicts were to scare protesters off "because the authorities can see that there are more and more demonstrations and people are starting to stand up and express their disagreement".
The "Network" probe is still going on and two people – one of whom has already alleged he was tortured – are awaiting trial in the northwestern city of Saint Petersburg.
Human rights organisation Memorial said the men convicted on Monday were political prisoners, describing them as leftist activists and anti-fascists.
Almost 50,000 people signed an online petition demanding that the case be closed.