Russia's most prominent opposition leader has been sentenced to 30 days in jail after he was arrested en route to an anti-Kremlin protest in Moscow.

Alexei Navalny, a vocal critic of President Vladimir Putin, was detained outside his home and sentenced hours later on charges of failing to follow police orders.

The 41-year-old had called for mass protests nationwide against corruption, with anti-graft demonstrations planned in more than 180 towns and cities.

Speaking to reporters shortly before he was sentenced, Navalny said: "The scope of the rallies was amazing, and so many people came out."

Shouts of 'Shame!' as Russian protesters held

A photo of Navalny being bundled into a police car was posted on Twitter by his wife Yulia, who said the protests were going ahead nonetheless.


:: 'Crooks and thieves' protests resonate with youth

Shortly after he was led from the court room, Navalny joked on Twitter the would have to miss out on a Depeche Mode concert while he was in jail.

The activist's spokeswoman also confirmed that electricity had been cut at his office - temporarily disrupting an online feed of nationwide demonstrations.

More than 800 people were arrested in Moscow, while in St Petersburg, about 500 protesters were forced into police buses at a rally which drew an estimated 10,000 people.

As demonstrators were taken away, hundreds of others shouted slogans including "Putin is a thief" and "Shame!".

The White House says the US condemns the Russian crackdown on peaceful protesters, and has called for the release of all those detained.

Image: Riot police have been deployed - with at least 800 protesters arrested so far

Police in the capital have put on gas masks and witnesses say pepper spray has been used against some protesters.

Mr Navalny angered officials in Moscow after he made a last-minute decision to change the main protest's location to one of the city's busiest thoroughfares.

The leader had been given permission to hold a rally away from the city centre, but claimed Russian authorities had pressured companies into refusing to supply him with sound and video equipment.

Before the protest began on Tverskaya Street, a stone's throw away from the Kremlin, prosecutors warned the rally was illegal and police would take "all necessary measures" to prevent disorder.

Image: Mr Navalny lost part of his sight after being attacked with green paint in April

Mr Navalny is mounting a long-shot bid to unseat Mr Putin in next year's election, but polls suggest he has little chance of being successful because of the president's high ratings.

On his blog last week, he wrote: "I want changes. I want to live in a modern democratic state and I want our taxes to be converted into roads, schools and hospitals, not into yachts, palaces and vineyards."

In April, the opposition leader suffered a chemical burn to his eye after a green liquid was thrown at his face - robbing him of some of his sight.