Russian opposition leader Alexei Navalny has been released after being arrested at a rally in Moscow.
Police wrestled Navalny into a patrol wagon moments after he appeared at a rally to urge voters to boycott what he said would be a rigged presidential election in March.
Video footage posted on social media showed Navalny appear on Moscow's main thoroughfare, a few hundred metres from the Kremlin, to join several hundred supporters taking part in the protest, which the authorities had said was illegal.
He had only walked a short distance when he was surrounded by helmet-clad police officers. They wrestled him to the ground on the pavement, and then dragged him feet first into the patrol wagon, the video footage showed. Navalny has been barred from running in the March 18 election which polls show incumbent president Vladimir Putin is on track to easily win.