Russian police detained dozens of protesters in rallies held in Moscow and St Petersburg on Thursday against President Vladimir Putin and to demand the right to free assembly.
More than 100 people attempted to gather in a central Moscow square where city authorities had denied them permission to demonstrate, chanting "Russia without Putin!" and "Let's stop dictatorship!"
Many were wearing the white ribbons that have become a symbol of protests against Putin, who returned to the Kremlin for a third term earlier this month.
Police have largely left crowds alone during winter protests that drew tens of thousands of people, but have been tougher lately, beating protesters at a rally on the eve of Putin's May 7 inauguration and breaking up attempted round-the-clock protests.
On Thursday, police in black helmets and body armor locked elbows and pushed against protesters, some of whom tried to break through the police line. Police pulled some protesters from the crowd and bundled them into vans as evening rush hour traffic passed by.
Police said they had detained about 60 protesters in the capital, state-run news agency Itar-Tass reported. In St Petersburg, they picked up at least eight of some 200 people at a peaceful protest.
"We don't need those who suppress freedom and truth ... I'm sick and tired of living in this disgusting country," said Angelina Tsaava, an elderly protester who held a poster calling the authorities "democracy's executioners".
Members of Strategy 31, a group named after the article the Russian Constitution that guarantees the right to free assembly, have tried to stage protests on the last day of every month with 31 days since 2009.
Opposition leaders say the government violates Russians' constitutional right to free assembly by requiring permission from local authorities for street demonstrations. Police often disperse unsanctioned rallies and detain protesters.
The anti-Putin protests, sparked by allegations of fraud in a December parliamentary election won by his party, were the biggest opposition demonstrations of his 12-year rule.
The protesters hope to keep the movement alive with a big rally on June 12, but city authorities have denied their request for permission to march down Moscow's central street and demonstrate on a square outside the Kremlin.
The ruling United Russia party, whose top post Putin ceded to Prime Minister Dmitry Medvedev on Saturday, has proposed a law designed to suppress protests by raising fines for violations at rallies to up to 1.5 million roubles ($48,000) from 1,000 roubles ($33.5).
($1 = 33.4767 Russian roubles)