Russia’s main opposition leader, Alexei Navalny, has been arrested along with dozens of others at an anti-corruption protest he organised in the capital, Moscow, witnesses say.
Protesters tried to prevent a police van from taking him away.
Thousands of people have joined rallies nationwide, calling for the resignation of Prime Minister Dmitry Medvedev over corruption allegations.
Police have been deployed in large numbers for the protest in the capital.
TV pictures showed demonstrators chanting “Down with Putin!”, “Russia without Putin!” and “Putin is a thief!”
Mr Navalny was detained as he arrived to join the rally, Russian media report.
In a tweet after his detention, he urged fellow protesters to continue with the demonstration.
“Guys, I’m fine. No need to fight to get me out. Walk along Tverskaya [Moscow main street]. Our topic of the day is the fight against corruption,” he said (in Russian).
Alexei Navalny is known for his anti-corruption campaign, which targeted senior officials close to the Kremlin.
He is barred from running for president against Vladimir Putin next year after being found guilty in a case he said was politicised.
