The Kremlin isn’t used to meaningful opposition—and it really shows. As Russian social media lights up with calls to take to the streets this Saturday in support of Alexei Navalny, Russian police have detained two close aides of the jailed opposition politician. Navalny was arrested last week after he returned to Russia from Berlin, where he had been recovering from a nerve-agent attack in August that he has blamed on the Kremlin. According to BBC News, his spokeswoman, Kira Yarmysh, and his lawyer, Lyubov Sobol, have also been arrested—though Sobol was later released. Meanwhile, Russians have been flooding TikTok with posts about the planned protests on Saturday, with teens filming themselves packing for the rallies and replacing Putin portraits in their schools with ones of Navalny. Police have warned that any gatherings will be “immediately suppressed.”