Russian police detain 50 at human rights protest

* Protesters call for authorities to respect freedoms

By Guy Faulconbridge

MOSCOW, Oct 31 (Reuters) - Russian police said they detained at least 50 people on 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 towards 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.

Moscow police spokesman Viktor Biryukov said about 50 people had been detained at the protest which he said was attended by about 100 people and 100 reporters.

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

Hundreds of police and interior ministry troops encircled the "march of the discontented" on Triumfalnaya Square, just a few km (miles) north of the Kremlin. Unlike previous protests, riot police were not used to make arrests.

Human rights groups say the Kremlin has muzzled the media and rolled back freedoms since Vladimir Putin was first elected president in 2000 and the situation has not improved under his protege, President Dmitry Medvedev.

Putin is believed by many diplomats and Russian citizens to be the real ruler in Russia despite stepping down as Kremlin chief to become prime minister in May 2008.

Lyudmila Alexeyeva, a Soviet dissident and one of Russia's best known human rights campaigners, 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, told Reuters as she was pushed towards metal barriers by a crowd of police, reporters and protesters.

(Additional reporting by Aidar Buribayev; Editing by Michael Roddy)