A voting app created by allies of prominent Kremlin critic Alexey Navalny was removed from Google and Apple’s online stores in Russia just as polls opened for parliamentary elections, according to a series of tweets from Navalny’s team on Friday. Ivan Zhdanov, a key ally of the jailed dissident, tweeted an image of an email he said was from Apple confirming the app was blocked. The email said the app, also called Navalny, was removed because Russia designates the Kremlin critic’s anti-corruption foundation as “extremist,” a reference to his now outlawed political movement. The app therefore contained content that is considered “illegal” in the country. The Navalny app included recommendations for the opposition leader’s “Smart Voting” strategy, which urges Russians to vote tactically in support of a candidate most capable of unseating an incumbent from the ruling party, United Russia, in the State Duma elections. Kremlin spokesman Dmitry Peskov said it considers the voting strategy to be a “provocation” and harmful to voters. American tech companies have been under an immense amount of pressure from the Russian government in recent months. Some have been handed down fines for not removing content that authorities consider to be “extremist” or “undesirable.” And Russian state media reported earlier this week that bailiffs visited Russia’s Google office on Monday. Russia’s internet watchdog Roskomnadzor has been demanding that Google and Apple remove the “Navalny” app from their online stores. The Russian Foreign Ministry issued a statement last Friday claiming the US Ambassador to Russia had been “summoned” to be told Russia has “irrefutable evidence of the violation of Russian legislation by the American digital giants” in regard to the elections. Neither Apple\n \n (AAPL) nor Google\n \n (GOOGL) has issued formal statements on the removal of the app from its online stores in Russia. Millions of Russians are expected to head to the polls over a three-day period starting Friday in elections taking place against the backdrop of an unprecedented assault on democracy over the past year. Navalny’s press secretary, Kira Yarmysh, tweeted that the decision of the American tech giants is a “huge disappointment” and an “act of political censorship” which “can’t be justified.” Zhdanov added Navalny’s team is considering filing lawsuits against Apple and Google. A person familiar with Google’s decision told CNN the company blocked the app in the Google Play Store due to legal “demands” from Russia’s internet regulator. The person said Google has received both publicly reported and private warnings of prosecution against its staff in Russia. Russian authorities threatened Google’s local staff in Russia with criminal prosecution, according to the person familiar with the company’s decision. Russian state media TASS reported on Thursday that a Russian official issued a direct warning that criminal legal action would be taken for continued deliberate “illegal actions and criminal inaction after receiving warnings.” The person familiar with the company’s decision said Google has blocked further downloads of the app but users who had already downloaded it should not be impacted. Peskov, the Kremlin spokesman, said he welcomed the decision to remove the app as the move was a “legal requirement” for both platforms to be compliant with Russian law. “That application is illegal on the territory of our country. Both platforms have received the requirement. And in accordance with the letter and spirit of the law, they made such a decision, most likely, but this question should be addressed to those services,” Peskov said.