Russian riot police beat opposition activists yesterday, detaining about 50 people ahead of a march against President Vladimir Putin in St Petersburg, a Reuters reporter said. They were detained when they left the offices of the liberal Yabloko party, in the centre of Russia's second city.

«It is very aggressive. I cannot understand why they do these things,» Nikita Belykh, leader of the Union of Right-Wing Forces (SPS) party, told Reuters.

Police also tried to arrest Belykh but he produced identity papers showing he was a candidate in Russia's December 2 parliamentary election and was left alone. Putin's opponents planned to march through the centre of St Petersburg yesterday, but authorities did not give permission and riot police blocked the streets in the centre of the city. The march was organized by Other Russia, a wide movement of Kremlin opponents, including free-market parties Yabloko and SPS.

Other Russia activists accuse Putin of cracking down on the freedoms won after the fall of the Soviet Union and of creating what they say is an unstable political system dependent on Putin alone. Putin, ranked by opinion polls as the most popular politician in Russia, is credited by supporters for cementing political stability and presiding over the longest economic boom for a generation.

Denis PINCHUK