MOSCOW: More than 50 people including opposition leader Alexei Navalny were detained Wednesday as police sought to break up a peaceful Moscow rally against the alleged impunity of law enforcement agencies.
Russian police moved in against the unsanctioned march amid cries of "shame" and "stop police terror."
At least 57 people were detained amid a heavy police presence, the OVD Info monitor said.
Some of the protesters wore T-shirts in support of Ivan Golunov, an investigative journalist who was last week arrested on allegedly trumped-up drugs charges.
One activist brandished a placard "I am Ivan Golunov" in the window of a police van.
Golunov's arrest sparked outrage and triggered unprecedented solidarity among Russians, with three top newspapers publishing the same front page "I am/we are Ivan Golunov" in giant letters on Monday.
The rally was initially called to press for the freedom of Golunov who was suddenly released, with the charges against him dropped, on the eve of the march following several days of public outrage.
Many saw Golunov's release as a Kremlin attempt to crush the new protest wave.
Many at the march called for reforms of Russia's tainted law enforcement agencies and the release from prison of many victims of police abuse.
On the eve of the march the Kremlin said the protest could interfere with festivities for Russia Day, a public holiday.
"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 a "I am Golunov" T-shirt, speaking before the march.
"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 massed in the city centre, urging authorities to release victims of police abuse like respected historian Yury Dmitriyev.
"We should not lull ourselves into complacency," said local lawmaker Maksim Reznik.
"We should use Golunov's case to draw attention to others."