Thousands of supporters of imprisoned opposition leader Alexei Navalny have protested across Russia against planned increases at retirement age, with a human rights group claiming that at least 153 of them have been detained by police.
The protests were a challenge for the authorities who expected high participation in the regional elections, which will also be held on Sunday, despite widespread indignation by the pension movement.
"The authorities are not listening to the people and that means it's time to go out," Navalny's team said in a statement prior to the protest.
The changes in proposed pensions, which are currently being processed in parliament, have reduced the popularity of President Vladimir Putin by around 15 percentage points. They are the most unpopular governmental measure since 2005 when measures were taken to eliminate the benefits of the Soviet era, which provoked protests by pensioners nationwide.
Navalny, excluded from state television and prevented from competing against Putin for president earlier this year, hopes to take advantage of public anger over the reform.
He had planned to lead a protest in Moscow on Sunday, but a court last month sentenced him for violating the protest laws and imprisoned him for 30 days. Navalny said the measure was designed to derail the protests that took place in 80 towns and cities, including Moscow and St. Petersburg.
OVD-Info, a rights organization that monitors arrests, said 153 Navalny supporters had been detained by police on Sunday in 19 towns and cities, including some of Navalny's closest aides.
In Moscow, where authorities rejected a request by Navalny supporters to protest, some 2,000 people gathered in the central Pushkin Square, officials and Reuters estimated.
Some of them shouted "Russia will be free" and "Putin is a thief" while riot police observed and ordered them to disperse or be prosecuted.
Another protester, Katya Shomnikova, 23, said: "They (the authorities) robbed me of my future life, we will have to correct what has been done, I want a better life for myself and my children."
A Reuters witness saw the police arrest at least one protester in Moscow.
After being amended by Putin, the reforms envisage raising the retirement age for men to 65 years of 60 years and to 60 years of 55 years for women. The average life expectancy for men is 66 and for women 77.