Police in Moscow and St. Petersburg have reported detaining more than 200 people at unsanctioned rallies today.
Demonstrators held the rally to demand the authorities respect Article 31 of the Russian Constitution, which guarantees the right to freedom of assembly.
Such rallies are held on the 31st of every month that has one.
Most people were detained only briefly. Among some 170 arrested in Moscow were politician Ilya Yashin and Yevgenia Albats, the editor in chief of the current-affairs magazine "Novoye vremya" (New times).
Police in St. Petersburg reported detaining about 60 people. Leading opposition figures, including Boris Nemtsov of the Solidarity movement and Maksim Reznik of Yabloko, were among demonstrators there.
A smaller rally was held outside the Russian Embassy in Kyiv, where demonstrators showed their support for rallies in Russia and warned that Ukraine could turn into a country where freedom of assembly was not respected.
compiled from agency reports