Russia has asked social networks, including video-sharing app TikTok, to stop the spread of posts encouraging minors to take part in unsanctioned rallies on Saturday in support of jailed Kremlin critic Alexei Navalny.
Navalny, President Vladimir Putin's most prominent critic, was detained at the weekend and later jailed for alleged parole violations after flying back to Russia for the first time since being poisoned by a military grade nerve agent.
He accuses Putin of ordering his murder, something the Kremlin denies. His supporters have called for nationwide protests against his detention on Saturday.
Communications watchdog Roskomnadzor late on Wednesday asked TikTok and Russia's largest social network, VKontakte, to prevent the dissemination of what it called information that could lead minors to engage in illegal activities that put their life and health in danger.
"We request that you immediately take comprehensive measures to prevent the distribution of such unlawful information on the TikTok platform," Roskomnadzor said in a statement.
A similar message was sent to Vkontakte.
Russian lawmakers in 2018 backed legislation to make it a jailable offense to call on anyone under 18 to attend unauthorized street protests, a move Navalny at the time said was designed to frustrate his own activity.