MOSCOW -- The popular mayor of Yaroslavl, an anti-corruption activist who is one of the few opposition figures in Russia to hold a major public office, was arrested late Tuesday and charged with bribery and extortion in a case that immediately set off accusations against the Kremlin of political intimidation.
The mayor, Yevgeny R. Urlashov, scored a stunning landslide victory in April 2012 against a Kremlin-backed candidate and transformed Yaroslavl, a city of 600,000 about 165 miles northeast of Moscow, into a symbol of hope for Russia's political opposition. At the time, the opposition was struggling to sustain its series of big street protests against Vladimir V. Putin.
"We have something to say to Mr. Putin," Mr. Urlashov said after his victory, standing outside a polling place. "Change is coming. Let democracy spring from the city of Yaroslavl."
But since then, Mr. Putin was successfully elected to a third term as president, and opposition figures have come under a furious barrage of criminal prosecutions intended to derail their budding political careers.
The arrest of Mr. Urlashov along with several senior members of his administration came a day after an announcement that he would top the list of candidates for Civic Platform, a political party created by the billionaire Mikhail D. Prokhorov, in regional parliamentary elections this September.
In a statement, Mr. Prokhorov, who owns the Brooklyn Nets basketball team, said, "The demonstrative seizure of the head of the city elected by the people is a blow to the human rights and freedoms of every citizen of Russia."
State-controlled television showed video of Mr. Urlashov, wearing a blue dress shirt open at the collar, being detained by armed security agents wearing green camouflage uniforms, bulletproof vests and black ski masks. Television also showed more than $420,000 in cash, bundled in stacks of 5,000-ruble notes, being pulled from an attaché case -- just a portion of more than $1.2 million in bribes that investigators said Mr. Urlashov and his aides had sought to extort from a contractor who provided cleaning and road repair services.
The authorities, apparently fearing public unrest, deployed a huge number of riot police officers throughout the city. But by evening the situation appeared calm, with only 150 to 200 people gathered in a square outside City Hall, shouting, "Free Urlashov!"
Mr. Urlashov, speaking on television, denounced the corruption allegations as political retribution. "Nothing has been confiscated," he said. "They looked, made a search in practically all of my deputies' offices, found nothing." He said that he had been set up by a man who is a member of United Russia, the party that nominated Mr. Putin for president.
"The man from whom I did not accept city cleaning, road repairs, wrote a report that I extorted bribes from him," he said. "I was warned that I would be removed one way or another." He added: "This is a political game, which is linked to the September 8th election. This is very unpleasant to me because I am a patriot of my country."
But even as Mr. Urlashov issued his forceful denials, federal officials were declaring his guilt. "Testimonies of some suspects confirm the suspicions of extortion and expose the mayor as the criminal mastermind," Vladimir Markin, the spokesman for the federal Investigative Committee, said. "Besides, one of the suspects has expressed his wish for a plea bargain, which implies the full acknowledgment of one's guilt and active cooperation with the police."
Officials said that they had also seized $500,000 from Mr. Urlashov's apartment, which they said his daughter was trying to hide with a neighbor, and an additional $200,000 from the office of Mr. Urlashov's press secretary, Svetlana Yefimova.
Mr. Urlashov was arrested along with a deputy mayor, Dmitry Donskov; the head of the city agency for municipal contracts, Maksim Poykalaynen; and a mayoral adviser, Aleksei Lopatin. They were charged with large-scale extortion and bribery -- charges that carry a potential jail sentence of 8 to 15 years.
Mr. Prokhorov, who ran unsuccessfully for president last year, said that he would still make a planned trip to Yaroslavl on Saturday in support of Mr. Urlashov's and Civic Platform's other candidates in the coming regional parliamentary elections.
In his statement, Mr. Prokhorov said the highly publicized detention of Mr. Urlashov by officers in camouflage was a "masks show" that "was staged with one purpose: to intimidate Yevgeny himself as well as all independent political figures and simply active citizens."
Alexandra Kozlova contributed reporting.
This article originally appeared in The New York Times.