Alexei Navalny, Kremlin critic, detained after trying to attend protest

Police have detained President Vladimir Putin's chief foe, who has broken the terms of his housearrest to attend a protest of several thousand just outside the Kremlin.

The unsanctioned demonstration on Tuesday came hours after Alexei Navalny, the anti-corruption campaigner, was found guilty of fraud and given a suspended sentence of three and a halfyears. A suspended sentence is essentially probation, meaning no jail time.

Navalny's brother was sent to prison.

The convictions are widely seen as a political vendetta against any opposition to Putin and his government.

Navalny, who has been under house arrest since February, broke its terms to attend the rally and was rounded up by police as he approached the site of the protest.

Convicted of defrauding cosmetics company

The verdict was to have been announced next month, but the court session was abruptly moved forward, leading to speculation that authorities wanted to impede possible protests if he were convicted. The verdict comes as Russians are preparing for New Year's and Orthodox Christmas.

Navalny and his brother Oleg were convicted of defrauding a cosmetics company. Oleg Navalny was also convicted on Tuesday and sentenced to the same prison term, but his was not suspended. The court also fined each of them about $8,800 USand ordered them to pay some $77,000in damages.

Oleg Navalny has been far less prominent than his brother and his going to prison could echo the Soviet-era practice of punishing the relatives of inconvenient people.

"This is the most disgusting and vile of all possible verdicts," Alexei said outside the court, before he was detained at the protest.

"The government isn't just trying to jail its political opponents we're used to it, we're aware that they're doing it but this time they're destroying and torturing the families of the people who oppose them," he said, and called for protesters to come out to the streets.

"The sentencing and the imprisoning of his brother Oleg Navalny seems aimed not only at punishing Alexei Navalny himself and stopping his anti-corruption work but also intimidating other critics of the government," said Hugh Williamson of Human Rights watch in a statement. "The Kremlin seems to be telling independent voices to expect a harsher crackdown in 2015,"

Rose to prominence by investigating official corruption

Still, some Russian officials suggested the sentence was too light and should be appealed by prosecutors, which is permitted under Russian law. Mikhail Markelov, a prominent parliament member from the United Russia party that is Putin's power base, told the news agency Tass that "everything should be done to achieve reconsideration of this sentence."

The brothers had both arrived at the courtroom with luggage, indicating they expected to be immediately sent to incarceration.

Navalny, a lawyer and popular blogger, rose to prominence with his investigations of official corruption and played a leading role in organizing massive anti-Putin demonstrations in Moscow in 2011 and 2012.

In a 2013 trial in a different criminal case, he was found guilty of embezzlement and sentenced to prison, but he was released the next day after thousands of people protested in the streets of Moscow. He was then handed a suspended sentence and finished a strong second in Moscow's mayoral election in September 2013.

At the conclusion of testimony in the latest trial, prosecutors asked for a 10-year sentence for Navalny. It was not immediately clear why the court chose the shorter term or why it was suspended, but that could reflect official concern about the prospect of unrest.

More than 16,000 peoplesaid on Facebook that they planned to attend theunsanctioned protest. The provocateur group Pussy Riot released a video Tuesday supporting the protest, featuring women sweeping snow from the square with brooms and then mounting them and flying off as witches.

Alexei Navalnyhad been ordered to remainunder house arrest until his appeals process is exhausted.