Russian communications watchdog Roskomnadzor warns Google and Apple to remove Alexei Navalny's election app from their stores.
Russia said Thursday the refusal by Google and Apple to remove jailed Kremlin critic Alexei Navalny
's app ahead of elections could be seen as interference in the country's domestic affairs.
Parliamentary elections are scheduled for later this month, with nearly all vocal Kremlin critics, including Navalny's allies, barred from running.
Last month Russian communications watchdog Roskomnadzor demanded that Google and Apple remove Navalny's app from their stores.
On Thursday, Roskomnadzor ramped up pressure on the Western tech giants, saying they could be held criminally liable if they continue to refuse to comply with Russian law.
"Criminal liability is foreseen for organising as well as taking part in the work of extremist organisations banned in Russia," the media watchdog said in a statement.
Failure to block the app "can be considered interference" in Russian elections and will lead to hefty fines, the statement warned.
Foreign ministry spokeswoman Maria Zakharova said US tech giants ignoring requests by Russian authorities to delete "illegal content" had become "systemic".
"Such arrogant, selective behaviour and demonstrative disregard for multiple requests by authorised Russian structures regarding content recognised as extremist is becoming truly unacceptable," she told reporters.
Opposition leader Navalny has this year seen his organisations declared "extremist" and banned, while all his top aides have fled.
The media regulator has since barred dozens of websites linked to Navalny including his main website navalny.com.
In a message from prison, Navalny has urged supporters to download an app that aims to help Russians to vote out candidates from the ruling United Russia party in the upcoming polls.
The "Smart Voting" tactic has led the increasingly unpopular United Russia party to lose a number of seats in recent local elections.
"If something can be called 'interference in Russian elections', it is the attempts of Roskomnadzor to block the Smart Voting app," Navalny's spokeswoman Kira Yarmysh said on Twitter. "Download them ASAP."