Moscow – Russian authorities arrested on Sunday prominent opposition leader Alexei Navalny and hundreds of Russians who took to the streets in one of the biggest movements staged throughout the country against President Vladimir Putin since he assumed power in 2012.

In Moscow, 7,000 to 8,000 Russians were on Tverskaya Street and the surrounding areas after the “Fund for Combatting Corruption” had called for protests against corruption in the state, and for the resignation of Prime Minister Dimitri Medvedev, whom his opponents say had gathered a fortune incompatible with his monthly salary.

Organizers of the protests had received an official permit to stage demonstrations in only a few Russian cities, while authorities had refused to grant them permits in the majority of other districts.

In their last attempt to prevent demonstrators from attending the protests, the Interior Ministry and the Public Prosecution had warned Russians from violating the law by demonstrating without permits.

After the protests kicked off at around 2 p.m. throughout Russian cities, police launched wide arrest campaigns among protestors. In Khabarovsk, they arrested 12 demonstrators out of 90 who had taken to the streets.

In Moscow, around 500 people were arrested, Interfax news agency reported on Sunday.

Deputy Interior Minister Alexander Gorovoi said on Sunday morning that authorities will “bear no responsibility for any possible negative consequences” for people who show up at the protests as the ministry “will not undertake an inspection campaign against terrorism during the demonstration.”

Navalny was one of the first Russians arrested during Sunday’s protests. Security officers arrested him the moment he had arrived to one of Moscow’s main squares along central Tverskaya Street.

“I’m happy that so many people came out (onto the streets) from the east (of the country) to Moscow,” Navalny said, moments before he was detained.

Police placed Navalny in a truck, while hundreds of protesters tried to prevent it from leaving.