A Moscow judge ruled Monday that former world chess champion Garry Kasparov has to serve out the five-day jail sentence he received after leading a protest against President Vladimir Putin that ended in clashes with police.

Kasparov was convicted of organizing an unsanctioned procession, chanting anti-government slogans and resisting arrest after Saturday's protest, held eight days before parliamentary elections.

In an appeal heard Monday, Kasparov argued that he had followed police orders and was illegally detained. He also cited contradictory testimony from police officers, who told the court in Saturday's hastily organized trial that they had been ordered before the rally to arrest Kasparov, one of Putin's fiercest critics.

Judge Yevgenia Naumova denied the appeal, ordering Kasparov to serve the remainder of his sentence.

Kasparov said he was being held in a cell at Moscow police headquarters. He was alone in the cell, which he said had a wooden floor. "I have no complaints about what is going on there," he told a reporter.

Monday's court session was attended by Kasparov's mother and several supporters.

Outside the courtroom, six members of a pro-Kremlin youth group held up a sack that had a sign saying "parcel for Garry." Inside was some dry bread, cigarettes and black tea.

Two shabbily dressed homeless men, who appeared to be part of the youth group's demonstration, held a sign that said "we support Kasparov."

Dozens were detained in Saturday's protest, which drew several thousand people.

In another opposition protest in St. Petersburg on Sunday, two leaders of the Union of Right Forces, a pro-business liberal party, were briefly detained.