MOSCOW -- Russian authorities have restricted access to the website of imprisoned opposition leader Alexei Navalny and to dozens of sites run by his allies, Navalny's team said Monday.
The action came amid mounting government pressure on opposition supporters, independent journalists and human rights activists ahead of Russia's parliamentary election. The September vote is widely seen as an important part of President Vladimir Putin's efforts to cement his rule before a 2024 presidential election.
The 68-year-old Russian leader, who has been in power for more than two decades, pushed through constitutional changes last year that would allow him to hold onto power until 2036.
Navalny's website, as well as the website of his top strategist, Leonid Volkov, and longtime ally Lyubov Sobol, were unavailable Monday. The sites of Navalny's Foundation for Fighting Corruption and a network of about 40 regional offices, which the Russian government outlawed as extremist groups last month, also could not be accessed, nor could the website of the Navalny-backed Alliance of Doctors union and an online page calling for Navalny's freedom.
According to Russia's state communications watchdog, Roskomnadzor, access to all of the sites was restricted at the behest of the Russian prosecutor general's office. In a statement to the Interfax news agency, Roskomnadzor confirmed blocking the websites, saying they were being "used for propaganda" of extremist groups.
"[They] have decided to completely wipe us out of the internet," Navalny associate Maria Pevchikh tweeted.
Navalny, who is Putin's most ardent political foe, was arrested in January upon returning from Germany, where he spent five months recovering from a nerve agent poisoning that he blames on the Kremlin -- an accusation rejected by Russian officials.
In February, Navalny was ordered to serve 2½ years in prison for violating the terms of a suspended sentence from a 2014 embezzlement conviction that he dismissed as politically motivated.
His arrest and jailing sparked a wave of protests across Russia's 11 time zones, in what appeared to be a major challenge to the Kremlin. The authorities responded with arrests of demonstrators and criminal prosecutions of Navalny associates.
Navalny's team pointed out Monday that the website of Smart Voting -- a project to support candidates most likely to defeat the ones from the Kremlin's dominant United Russia party in various elections -- remained available.
Volkov, the strategist, suggested that authorities might block the strategy site "closer to the election" in September, in which Navalny's team plans to deploy the Smart Voting project.
Ivan Zhdanov, a Navalny ally, said in an Instagram post that the politician's team was "was not surprised" by the blocking of the websites "and therefore ready" for them. Zhdanov urged supporters to follow Navalny's team and its members on social media, "where it's harder to block us," and to download a mobile app that contains all the recent investigations and the Smart Voting project.
"An app cannot currently be blocked," Zhdanov wrote.