Russian police detained around 200 people, including several prominent opposition figures, at a meeting of independent and opposition politicians in Moscow on Saturday, the interior ministry said.

The detentions come amid a crackdown on anti-Kremlin sentiment, following the arrest and imprisonment of opposition politician Alexei Navalny who returned to Russia in January after recovering from a nerve agent poisoning in Siberia.

The Moscow forum, scheduled for Saturday and Sunday, was a gathering of municipal deputies from all over the country, Andrei Pivovarov, the event’s organiser and executive director of Open Russia, a British-based group founded by exiled former oil tycoon and Kremlin critic Mikhail Khodorkovsky, told radio station Echo Moskvy.

As the forum got underway, police entered the building and began detaining attendees and taking them to police vans waiting outside, video footage from TV Rain and Russian news agencies showed.

The Moscow branch of Russia’s interior ministry said around 200 people had been detained and that an investigation was underway.

Police said those detained were not following the appropriate anti-coronavirus health measures even though footage showed most of them wearing masks. They said some of those attending the forum had links to an “undesirable organisation”.

-A significant portion of participants lacked personal protective equipment- the police said. -Members of an organisation whose activities are considered undesirable on Russian territory were among the participants.-

OVD-Info, which monitors the detention of political protesters and activists, put the number of detainees at more than 170.

-The finale of the short forum was very symbolic: deputies in police vans and masked police twisting people’s arms- one detainee, opposition politician Ilya Yashin, wrote on Facebook.

-But no one promised us freedom on a silver platter. Russia will still be free.-

Vladimir Kara-Murza, vice-president of the Free Russia Foundation, a Washington-based non-profit organisation, shared a picture from the inside of a police van after he was detained.

TV Rain said Yevgeny Roizman, the former mayor of Yekaterinburg, and Moscow city councillor Yulia Galyamina were also detained.

Open Russia is one of more than 30 groups that Moscow has labelled as undesirable and banned under a law adopted in 2015.