Moscow angrily told the US Embassy to "take care of your own affairs" after Washington's diplomatic mission raised concerns about restricting media freedom in Russia.
US Embassy spokeswoman Rebecca Ross said Tuesday she was concerned about crackdown on journalists in Russia.
"Watching the arrest after the arrest of Russian journalists – it looks like a concerted campaign against #MediaFreedom," she tweeted.
"Take care of your own affairs," the Russian Foreign Ministry tweeted late Tuesday.
On the same day, the FSB security agency, the successor to the Soviet-style KGB, arrested a respected former journalist, Ivan Safronov (30), on suspicion of treason.
His detention triggered a riot among supporters and journalists who said his arrest was a punishment for reporting on the Russian defense sector.
A member of Safronov's defense team, Yevgeny Smirnov, said the former journalist, who previously worked for the Kommersant and Vedomosti newspapers, has been suspected of working with the Czech secret service since 2012.
The FSB investigators believe that the Czech secret service is operating under the leadership of the United States, Smirnov told AFP.
According to the FSB, Safronov has collected confidential information about the Russian military, defense and security and has passed it on to a NATO member country's secret service.
On Monday, a reporter from the northwestern city of Pskov was fined nearly $ 7,000 for "justifying terrorism," which sparked an outcry.
The prosecutor had requested that Svetlana Prokopyeva be sentenced to six years in prison for commenting on a bomb attack.
All major television stations in Russia are under state control.
Journalists working for print and online outlets have recently complained about increasing press freedom restrictions and the Kremlin's pressure.
(This story was not edited by NDTV staff and is generated automatically from a syndicated feed.)