The demonstrations kicked off in Russia’s far east city of Vladivostok and spread to the west as the day progressed. Videos posted on social media showed crowds of people gathered in Vladivostok and a number of cities across Siberia and central Russia.
One video showed a small protest in the city of Yakutsk, where temperatures dropped to -53 degrees Celsius (- 63 Fahrenheit) on Saturday.
The demonstrations have not received an official government permit and the authorities have warned people not to attend them.
Several allies of Navalny have been detained this week for inciting the protests, including his spokesperson Kira Yarmysh, Anti-Corruption Foundation investigator Georgy Alburov and opposition activist Lyubov Sobol.
The coordinator of Navalny’s Moscow office, Oleg Stepanov, was detained on Saturday, according to a tweet from Navalny’s Moscow team. A protest in the Russian capital was due to start at 2 p.m. local time (6 a.m ET).
The Russian Ministry of Foreign affairs has accused the United States of encouraging the protests after the US Embassy in Russia posted an alert on its website advising US citizens to avoid the demonstrations.
In a tweet posted on Saturday, the ministry said that posting information about the rallies was “in line with Washington’s provocative policy of encouraging protests in countries whose governments are seen by US as undesirable.”
Under Russian law, an official appeal for approval of a protest has to be made to local authorities at least 10 days before the event. Navalny was only arrested less than a week ago, so the organizers had insufficient time to launch an appeal.
Russian internet regulator said Thursday it was planning to fine major social networks, including Twitter, Facebook and TikTok, for “spreading information prohibited by law and aimed at attracting minors to participate in unauthorized mass public events.”
CNN’s Fred Pleitgen, Zahra Ullah and Anna Chernova in Moscow contributed reporting.