By Tom Balmforth and Gabrielle Tétrault-Farber

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, which the Kremlin denies. His supporters have called for nationwide protests on Saturday, hoping to press the Kremlin into letting him walk free ahead of parliamentary elections in September.

In Brussels, responding to Navalny’s arrest, European Union lawmakers called for the bloc to stop the completion of the Nord Stream 2 gas pipeline to take Russian natural gas to Europe.

Several of Navalny’s allies in Russia said police had come to their homes, including that of his spokeswoman Kira Yarmysh, who was later detained for allegedly disobeying police orders and violating protest laws.

“The police have started forcing open the door and are saying: come out, you’re coming out on Saturday anyway and we’re going to detain you,” Yarmysh wrote on Twitter before she was detained.

Earlier, Georgy Alburov, another Navalny ally, said he was taken into police custody at a Moscow train station.

Vladlen Los, a Belarusian lawyer for Navalny’s group, said he had been detained, told to leave the country by Monday, and barred from re-entering Russia until November 2023.

Police also detained Navalny ally Lyubov Sobol, her lawyer said. She had urged people to take part in the protest, though the reason for her detention was not immediately clear.

Authorities have said the planned rallies are illegal and that people who make such calls would be held to account.

Communications watchdog Roskomnadzor said it would seek to fine social media platforms for what it said was illegal content urging minors to take part in illegal protests.

Some prominent Russians – including ice hockey star Artemi Panarin as well as rappers, actors, writers and others – posted messages and videos of support for Navalny on social media. TikTok was flooded with videos promoting the protests. (Additional reporting by Alexander Marrow, Maxim Rodionov, Anton Zverev, Maria Grabar Editing by Peter Graff)