Alexei Navalny, a leader of the Russian opposition, was released on Sunday after 50 days of arrest.
In September, he was released after 30 days of arrest aftre organizing an unauthorized protest.
However, he was arrested again on the very day of his release due to a demonstration against the pension reform supported by the government. The reform implies raising the retirement age to 60 for women and 65 for men. Over a thousand people were detained during the protests against the pension reform across the country.
Navalny has been charged for a number of times because of his opposition activities. He was not permitted to take part in presidential elections in March of this year due to his conviction on charges of financial crimes, which, according to the opposition leader, are fabricated.