MOSCOW -- Russian authorities arrested former world chess champion Garry Kasparov on Saturday and sentenced him to five days in prison after he helped lead a protest against President Vladimir Putin that ended in clashes with police.
Kasparov, one of President Vladimir Putin's harshest critics, was charged with organizing an unsanctioned procession of at least 1,500 people against Putin, chanting anti-government slogans and resisting arrest, court documents said. His assistant said he was beaten during the demonstration.
At the hastily organized trial, two police testified that they had been ordered before the rally to arrest Kasparov.
"What you read is the fruit of a fantasy dictated on orders from above," Kasparov told the court.
The violence came amid an election campaign in which some opposition political groups have been sidelined by new election rules or have complained of being hobbled by official harassment.
The Kremlin has mounted a major campaign to orchestrate a crushing victory for Putin's United Russia party in Dec. 2 parliamentary elections -- perhaps to ensure that Putin can continue to rule Russia even after he steps down as president in May. The constitution prevents him from serving three consecutive terms.
The fracas also comes at a time of growing concern in the West over the state of democracy in Russia, with western critics saying freedoms have been curtailed during Putin's eight years in office. Putin accuses the West of meddling in Russian politics.
Kasparov and dozens of other demonstrators were detained after the rally which drew several thousand people.
The opposition activist was forced to the ground and beaten, his assistant Marina Litvinovich said in a telephone interview from outside the police station where Kasparov was held.
"Putin's brakes don't work," Kasparov told a reporter in the courtroom. "I didn't hear any orders from police, unless you count the strike of a police club as an order."
Protesters were surrounded by metal fences and funneled through metal detectors while hundreds of uniformed police and interior ministry troops stood by. Men in black coats who refused to identify themselves circulated through the crowd shooting video.
After the rally ended, a line of helmeted police tried to prevent a march and channel protesters back toward a nearby Metro station.
Among the dozens of demonstrators arrested was Eduard Limonov, author and leader of the National Bolshevik Party, Kasparov's closest partner in a coalition of anti-Kremlin organizations. Supporters said he was later released.
Police in other Russian cities, including Nizhny Novgorod and Samara, detained local opposition protest organizers, according to the Interfax news agency.
Kasparov's coalition, which includes radicals, democrats and Soviet-era dissidents, has drawn wide media coverage but generated little public support.
Its ranks have expanded, though, as more mainstream political parties complain that officials have excluded them from freely contesting the upcoming elections.
On Friday, the Moscow offices of Kasparov's political organization were searched by police, who seized campaign materials, and the headquarters of the opposition Union of Right Forces party was hit by vandals, the groups said.
Police in Moscow and several other cities have used force to break up several so-called Dissenters Marches in the past year, sometimes beating protesters with truncheons.
The city gave organizers a permit for Saturday's rally but forbid them to march.