Russian opposition leader and former world chess champion Garry Kasparov failed yesterday in an appeal against his detention during a street protest at the weekend, one of his aides said.

Mr Kasparov was one of dozens arrested in protests in Moscow and St Petersburg that were broken up by riot police using truncheons. The US and European powers have expressed concern at the police tactics a week before parliamentary polls.

A court gave Mr Kasparov a five-day sentence for organising an illegal protest.

Marina Litvinovich, a senior member of Mr Kasparov's United Civil Front, said from Moscow's Meshchansky court that a judge had rejected his appeal against the term.

"The judge considered the complaint and left the previous court's decision in force, which means Garry will stay in detention," she said by telephone. "Garry is still in court but in five minutes he is likely to be transferred back to Petrovka 38," she said, referring to the Moscow police headquarters where Mr Kasparov is being held.

The weekend rallies were held to protest against a December 2 parliamentary election which the opposition says is unfairly weighted in favour of President Vladimir Putin's United Russia party. Opinion polls say the party will win by a huge margin.

The US criticised Mr Kasparov's detention, saying it was concerned "by the aggressive tactics used by Russian authorities against opposition protesters".

European Commission President José Manuel Barroso described the tactics of Russian police as "heavy-handed".

Kremlin officials say the protesters do not have popular support and are dangerous radicals trying to destabilise Russia with help from foreign governments.

Mr Kasparov's movement is not running in the election and is much smaller than other opposition groupings.

Earlier, Mr Kasparov's supporters said they were concerned about him because they had been unable to establish where he was being held and his lawyer had not been given access.