Police detained 60 opposition activists on Saturday to keep them from protesting in downtown Moscow.
Some were detained as they were approaching the protest site, while others were hustled onto police buses as soon as they began chanting against Prime Minister Vladimir Putin. A banner they unfurled read, "Death to Kremlin occupiers."
Organizers hadn't received permission to hold the protest, the latest in a series held at the end of every month that has 31 days. The number corresponds to Article 31 of the Constitution, which guarantees freedom of assembly.
Small protests also were held Saturday in other cities. The Article 31 rallies are separate from the massive demonstrations that drew tens of thousands in Moscow on Dec. 10 and Dec. 24 to demand fair elections and an end to Putin's rule.
Associated Press reporters and photographers saw at least 20 people detained at Saturday's rally in Moscow. Police said a total of 60 were rounded up. It was unclear whether they would be held overnight.