Moscow, 28 September 2021 (dpa/MIA) - Even after a parliamentary election that gave a resounding victory to the ruling party, Russian authorities are continuing to take action against leading opponent of the Kremlin Alexei Navalny, who is imprisoned in a prison camp. New investigations have been launched into the 45-year-old for founding and participating in an extremist community, Russia's investigative agency announced on Tuesday. Several known supporters of Navalny are also being investigated, including the lawyer Lyubov Sobol and the opposition figures Ivan Zhdanov and Leonid Volkov, who live abroad. In June, a Russian court - despite international criticism - classified the Anti-Corruption Fund and other organizations of Navalny's as extremist and thus banned them. Critics complained that this was intended to politically eliminate supporters of the leading opposition figure. Navalny, who only narrowly survived a poison attack last year, has already been imprisoned since the beginning of the year in a penal camp about 100 kilometres east of Moscow for another criminal offence. A corresponding sentence passed in February has been criticized as politically motivated. The Kremlin critic's lawyers calculated at the time that he could be released in the summer of 2023. Now, however, his supporters fear that Navalny could remain in prison for much longer. Navalny's press secretary Kira Yarmysh wrote on Twitter on Tuesday, referring to the State Duma election more than a week ago, "Everyone has been asking if the pressure will ease after the elections. Well, here is the answer." It was already the fourth criminal case against Navalny that had been opened since his detention.