By Vladimir Soldatkin and Jack Stubbs
MOSCOW/ST PETERSBURG (Reuters) - Police detained more than a hundred opposition activists on Saturday for taking part in a wave of anti-Kremlin protests across Russia in support of jailed opposition leader Alexei Navalny ahead of a presidential election in March.
Under gray skies and intermittent rain, over two thousand people gathered in central Moscow's Pushkin Square and chanted "Russia will be free" and "Russia without Putin" before walking towards the Kremlin and parliament.
Police briefly detained a few people, but did not charge anyone. It was a different story at rallies in other cities however, and the OVD-Info monitoring group, a non-profit organization, said 132 people had been detained in 25 towns.
Navalny, who is serving a 20-day jail term for violating rules on public meetings, called the rally in Moscow and other cities to coincide with Putin's 65th birthday.
Putin, who has dominated Russia's political landscape for almost 18 years, is widely expected to run for what would be his fourth term.
Navalny hopes to run too, despite the central election commission declaring him ineligible due to a suspended prison sentence he says was politically-motivated.
One of the Moscow protesters held a homemade poster of Putin sitting on a mountain of banknotes wearing a crown with the legend: "Happy Birthday you little thief!"
Others carried copies of the Russian constitution and posters citing their right to protest, some waved Russian flags, and a few carried inflatable yellow ducks, a jokey reference to the fact that Navalny accused Prime Minister Dmitry Medvedev of owning a lavish estate with a duck house.
Medvedev called the allegations against him politically-motivated nonsense.
In St Petersburg, Putin's home city, some 1,500 activists waving red and white banners in Navalny's support gathered in a large public square before heading for the city's main street shouting "Putin is a thief" and "Freedom."
PROTESTS MORE MODEST IN SIZE
The size of Saturday's Moscow rally and others across Russia looked more modest than Navalny-backed mass protests in March and June which were widely recognized to be some of the biggest since 2012.
Many of the Moscow protesters were teenagers or in their twenties.
Carrying a yellow duck, Ulugbek Apsapayev, 17, said he had turned up because he wanted a better future for Russia.
"The duck is a sign that we support Alexei Navalny who also wants only good things for the country. But unfortunately we only have Vladimir Putin and his gang in power."
Putin is popular across the country however, especially outside major cities where his strong leadership style and tough foreign policy stance goes down well. He is expected to confirm later this year that he will run for another six-year term.
Opinion polls show he would comfortably beat Navalny if the opposition leader was allowed to run. Navalny says such polls are meaningless because there is no fair political competition.
Moscow authorities had refused to approve Saturday's rally and such events have often ended with mass detentions, but a Reuters reporter on the scene said police largely showed restraint this time.
However, at a similar rally in the Urals city of Yekaterinburg, a Reuters reporter saw police detain at least eight people among a crowd of over 1,000 protesters.
(Additional reporting by Gabrielle Tetrault-Farber in Moscow and Natalya Shurmina in Ekaterinburg; Writing by Andrew Osborn; Editing by Clelia Oziel)