MOSCOW: Moscow has told the US embassy to "mind your own business" after Washington's diplomatic mission raised concern about curbs on media freedom in Russia.

Rebecca Ross, the spokeswoman for the US embassy, on Tuesday expressed concern about a clampdown on journalists in Russia.

"Watching arrest after arrest of Russian journalists - it's starting to look like a concerted campaign against MediaFreedom," she tweeted.

"Mind your own business," the Russian foreign ministry tweeted in response late Tuesday.

Earlier that day the FSB security agency, the successor to the Soviet-era KGB, arrested a respected former journalist, Ivan Safronov, 30, on suspicion of state treason.