Vladimir Putin critic Alexei Navalny detained ahead of nationwide anti-Kremlin protests

Around 100 protesters also detained by police in central Moscow

Alexei Navalny (dressed in a blue shirt) is detained by police outside his apartment in Moscow, Russia (Navalny Anti Corruption Fund via AP)

The leading Vladimir Putin critic Alexei Navalny has been detained by authorities on his way to a protest in Moscow, his wife has claimed, ahead of a day of anti-Kremlin protests across Russia.

Mr Navalny's wife Yulia said he was arrested at the entrance to his home in Moscow about half an hour before the demonstration was due to begin.

"Alexei was detained in the entrance hall of our building," she wrote on social media. "He asked me to tell you that the plans (for the protest) are unchanged."

A live internet feed run from the opposition leader's office went offline and his spokeswoman said electricity to the office was cut.

Reuters witnesses saw a police car leaving Mr Navalny's apartment compound at high speed, followed a few minutes later by a minibus carrying around 10 policemen.

Around 100 protesters were detained near central Moscow's Pushkin Square, witnesses told Reuters, as police uesd pepper spray.

Eleven demonstrators were also arrested in Vladivostok, according to OVD-Info, a website that monitors political repressions.

Thousands are expected to protest against corruption, part of Mr Navalny's long-shot drive to unseat President Vladimir Putin next year by tapping into anger over what he says is official fraud.

There is a risk of violence as Mr Navalny's supporters descend on Moscow city centre for an unauthorised protest.

Around the venue for the planned protest, on Tverskaya Street in central Moscow, hundreds of riot police and military conscripts were waiting.

Mr Navalny's website reported that protests were held in more than half a dozen cities in the Far East, including the major Pacific ports of Vladivostok and Khabarovsk and in Siberia's Barnaul.

Photos on the website suggested turnouts of hundreds at the rallies.

Mr Navalny has announced his candidacy for the presidential election in 2018.

He was jailed for 15 days after the March protests. In April, he suffered damage to one eye after an attacker doused his face with a green antiseptic liquid.