Seven opponents of President Vladimir Putin were sentenced to prison terms ranging from two and a half to four years on Monday over a demonstration that turned violent, and riot police detained over 100 people protesting outside the court.
The protesters, who blame police for the violence in central Moscow in 2012, demanded the release of the defendants and shouted "shame" and "Maidan" - a reference to the Kiev square that has been the focus of protests that brought the overthrow of Ukrainian President Viktor Yanukovich.
Relatives and lawyers had feared upheaval in neighbouring Ukraine, where police were among the dead in a conflict the Kremlin blames on opposition leaders and the West, would prompt the court to send a firm signal by imposing prison sentences.
An eighth defendant was given a suspended sentence that allows her to avoid jail; but the rulings caused outrage among Kremlin critics who see the prisoners as victims of a clampdown on dissent marking Putin's election to a third term as president.
Opposition activists said more than 230 people were detained by riot police who worked their way through the gathering at the courthouse, detaining protesters one by one. Police put the figure at more than a hundred.
The judge on Friday had found the defendants guilty of rioting and attacking police at a protest on May 6, 2012, the day before Putin, in power since 2000, returned to the presidency after a stint as prime minister.
The defendants blame police for the clashes that erupted and pleaded not guilty.
The sentences are likely to draw criticism from the United States and European countries that have expressed concern about the "Bolotnaya" trial and have accused Russia of restricting the freedom of assembly and expression.
Government opponents called for a protest outside the Kremlin later on Monday. Defence lawyers said they would appeal the verdicts.