Russian opposition leader Alexei Navalny was released on Sunday after being jailed for 20 days, news agency Reuters reported. Navalny was held on charges of staging an illegal protest on September 24.Navalny was in jail for a month for a protest he organised on January 28, violating Russias strict laws which forbid any public event without city halls authorisation. He accused authorities of sending him to prison to keep him from holding a protest on September 9 against the governments retirement age hike that coincided with local elections. Navalny has called some of the biggest protests in Russia in recent years. His anti-corruption rhetoric is especially popular among younger people who follow his online channels and blogs.He was barred from taking part in Russias presidential election in March and served a month in prison in June after organising demonstrations ahead of Putins fourth inauguration in May. He was freed from prison the same day the World Cup started in Russia. The Yale-educated lawyer has faced a string of charges since he became the leading opposition figure in Russia, campaigning against Putins rule at mass demonstrations in 2011 and 2012.