The Kremlin says the arrest of three senior officers of Russia's top spy agency reflects a no-holds-barred fight against corruption.

Russian President Vladimir Putin's spokesman Dmitry Peskov said Monday when asked about the arrests that the Kremlin has coordinated anti-corruption efforts that targeted "all agencies and officials of any rank without exclusion."

Col. Kirill Cherkalin, a section chief in the economic security department of the Federal Security Service, or FSB, was arrested last month along with two other senior FSB officers on suspicion of taking bribes. Russian media have reported that the suspects were found in possession of 12 billion rubles (about $186 million) in cash.

The FSB, the main KGB successor, has wielded a growing clout, and the officers' arrest has sent shockwaves across Russia's political scene.