Police said they detained at least 50 people Saturday at an unsanctioned human rights protest in central Moscow, but protesters put the number higher.

Police dragged off dozens of people to waiting buses and jostled scores of reporters toward metal barriers while protesters continued to chant “Freedom!” and “Respect the constitution!”

“I want Russia to be free, not to rot in a policeman’s nightmare,” said a protester in a black mask who refused to give his name for fear of reprisals.

Police spokesman Viktor Biryukov said about 50 people had been detained at the so-called Dissenters’ March, which he said was attended by about 100 people and 100 reporters.

Opposition activists said 70 people had been detained and 500 people had showed up.

Police said Sunday that all the detainees had been released.

Hundreds of police and Interior Ministry troops encircled the rally on Triumfalnaya Ploshchad. Unlike previous protests, riot police were not used to make arrests.

Lyudmila Alexeyeva, a Soviet-era dissident and head of Moscow Helsinki Group, attended the protest with a police colonel, an escort she said was needed to ensure she was not crushed by the crowds. “I came here to defend the constitution,” Alexeyeva, 82, said as she was pushed toward metal barriers by a crowd of police, reporters and protesters.