By Steve Gutterman
MOSCOW (Reuters) - A Russian opposition politician, whose election as a city mayor last year embarrassed President Vladimir Putin, was detained on Wednesday on corruption charges.
Yevgeny Urlashov and his allies said the arrests were intended to silence dissent and hurt his party's chances in a September election.
A spokeswoman for Urlashov - mayor of Yaroslavl, 250 km (150 miles) northeast of Moscow - said police had dragged him from his car when he stopped at a roadblock late at night. The Interior Ministry confirmed his detention.
Federal investigators said Urlashov, his deputy and two other officials were suspected of extorting a 14-million rouble ($425,000) bribe from the head of a firm that has street cleaning and repair contracts in Yaroslavl. They could be jailed for 15 years if convicted.
News agencies said police searched their homes and the mayor's office.
"It is obvious that this night-time show ... had a single aim: to scare Yevgeny and all other independent politicians and active citizens of Russia," billionaire Mikhail Prokhorov, leader of the independent Civil Platform party, said in a statement.
Putin's critics accuse him of cracking down on the opposition since his return to the Kremlin in May 2012 and several opposition leaders have faced criminal charges. The Kremlin denies using the judiciary for political ends.
Urlashov, a member of Civil Platform's governing committee, defected from the ruling United Russia party in 2011 to join a protest movement that mounted the biggest opposition rallies of Putin's 13 years in power.
His landslide victory in Yaroslavl in April 2012 underscored discontent with United Russia.
An aide said that Urlashov had called the mayor's office after being detained, and quoted him as saying the allegations were a "provocation" by a company that had done poor quality road work, but were also intended to upset Civil Platform's plans for the election of a regional legislature on September 8.
Urlashov was to lead Civil Platform's list of candidates in the election, and party chief Prokhorov - a metals tycoon who owns U.S. basketball team the Brooklyn Nets and placed third in the March 2012 presidential election won by Putin - is to travel to Yaroslavl on Sunday to show support.
"This is pressure against me and my allies in connection with the September 8 election and with Mikhail Prokhorov's visit," the aide quoted Urlashov, 45, as saying.
Urlashov's spokeswoman, Svetlana Yefimova, was quoted as saying on the Civil Platform website that police had "pulled him out by the scruff of the neck and drove him away without explaining the reason" after stopping his car after midnight.
(Additional reporting by Maria Tsvetkova; Writing by Steve Gutterman; Editing by Timothy Heritage and Robin Pomeroy)