St. Petersburg, Russia (CNN)Russian police arrested 290 protesters in 26 cities as marches took place against President Vladimir Putin on the leader's 65th birthday, according to independent monitoring group OVD.
Russian police arrest hundreds in protests on Putin's birthday
Thousands attended the marches on Saturday, held by supporters of Putin's only real political opponent, activist Alexei Navalny, who is serving a 20-day jail term for organizing an unauthorized public meeting.
It is very difficult to legally organize protests in Russia, where public assembly laws have been tightened several times since Putin's current presidential term began in 2012.
Navalny, 41, has said he intends to run for president in the next election, despite carrying an embezzlement conviction that prevents him from doing so. He claims that conviction was bogus and politically motivated to block his presidential bid.
Navalny has been jailed three times this year.
Putin is widely expected to run in the March vote. He has served as either Prime Minister or President of the country since 1999.
Protesters on Saturday called for him to retire and for Navalny to be released from jail.
Dozens of protesters detained have since been released. The highest number of arrests were in Putin's birthplace of St. Petersburg, where 68 people were taken into police custody, according to OVD.
"I'm not satisfied with the current situation in the country. I'm not happy with the authorities. We practically don't have freedom of speech. We have strict censorship on television, and the only contender opposed to Putin isn't allowed in any way to take part in the elections," one woman at the St. Petersburg rally told CNN.
A man at the rally said that it was very unlikely that Navalny would actually be allowed to run in the next vote.
"But there is a chance to change everything in Russian political life," he said.
Navalny has throngs of supporters, largely because of his anti-corruption campaigning, which has thrived online.
He has been running an unofficial election campaign across the country.