Hundreds of protesters have been detained by riot police in cities across Russia, as some of the largest anti-government protests in years swept the country.

The call to protest came from the opposition politician and anti-corruption campaigner Alexei Navalny, who was himself detained at the Moscow demonstration. A monitoring group said at least 850 people were detained in Moscow alone, while the news agency Tass gave a figure of 500.

Police said about 7,000 people attended the Moscow rally on Sunday, though the real number may have been much higher. The crowds surged down the length of the city’s main thoroughfare, Tverskaya. A police helicopter flew overhead and thousands of riot police were on duty across the city centre.

The size and scope of the demonstrations pose a challenge to the Kremlin, a year before elections in which Vladimir Putin is expected to win another six-year term.

Soon after arriving, Navalny was bundled into a police bus, which was unable to drive away for several minutes as crowds set upon it and tried to free him. Protesters even pushed parked cars in front of the bus to stop it moving, but were later beaten away by riot police. There were isolated clashes with riot police and shouts of “shame” and “Russia will be free”.

The protests were ostensibly a demand for answers to a video made by Navalny and his team about corruption linked to the prime minister, Dmitry Medvedev. The video, which alleges that Medvedev has amassed a collection of luxury mansions, yachts and vineyards, has been watched on YouTube more than 11m times. There has been no official response to the allegations except to dismiss them out of hand.

The gatherings in Moscow and most other Russian cities were denied official permission by police on a variety of pretexts. In Moscow, police moved to detain protesters who were shouting slogans or holding placards, those who were acting aggressively, or often simply at random.

(The Guardian)