Momentum is building in Russia for widespread protests this weekend in support of jailed opposition leader Alexei Navalny.
Videos have been posted on TikTok, Russia’s most popular iPhone app, encouraging people to defy authorities and turn out.
Young Russians in particular have flooded the social media site using the hashtags #freenavalny and #23Jan.
Protesters have already clashed with police in the southeastern city of Khabarovsk in one of up to 70 marches this weekend.
One TikTok video tells demonstrators to pretend they are American tourists if questioned by the police.
Others show Navalny supporters packing their bags ready for demonstrations, recommending they bring milk to help counter the effects of tear gas, and some depict students removing pictures of President Vladimir Putin from classrooms and replacing them with photos of Mr Navalny.
The clips have been watched more than 60 million times, prompting the state censor to demand TikTok remove them.
Mr Navalny returned to Moscow from Berlin last weekend, where he’d spent months being treated for Novichok poisoning.
He was arrested on arrival in Moscow and charged with breaking his bail conditions – and is facing a potential three-and-a half-year jail term if found guilty.
His detention has been widely condemned by the international community, which believes the Russian state was behind attempts to kill him.
The demonstrations due to take place this weekend could be the largest against Mr Putin since 2018.
They come at a high risk when coronavirus rates are still surging in Russia and police already have an excuse to disperse large gatherings.
Officials have enforced a crackdown in the run-up to the demonstrations, arresting members of Navalny’s team, including his spokeswoman Kira Yarmysh.
They have also launched an investigation into the calls for protests on TikTok.
But anger has hardened against the president this week after the Navalny team released a documentary exposing a vast and opulent palace built by Russia’s leader on the Black Sea coast.
The programme claims the complex – 39 times larger than Monaco – cost £1bn to build and was funded through illicit money.
It is said to have a casino, an underground ice hockey complex and a vineyard.
“It has impregnable fences, its own port, its own security, a church, its own permit system, a no-fly zone, and even its own border checkpoint,” Mr Navalny says in the video.
Forty million people had viewed the video on YouTube within 40 hours of it being published.