* Defendants had protested against Putin's return to Kremlin
* Defendants charged with rioting, attacking police
* Police round up 200 outside courtroom
* Sentencing delayed until after Sochi Games
* Freed ex-tycoon Khodorkovsky denounces "show trial" (Adds guilty verdict, sentenced scheduled for Monday)
By Gabriela Baczynska
MOSCOW, Feb 21 (Reuters) - A Russian judge on Friday convicted eight defendants of assaulting police during a protest against Vladimir Putin, in what activists called a "show trial" designed to make clear the president would tolerate no dissent.
Outside the courthouse, police pushed into a crowd that had gathered to support the defendants, grabbing people and hauling them away as others shouted: "Shame!" Police said they detained about 200 people for attempting to violate public order.
The convictions, which were widely expected, coincided with political turmoil in neighbouring Ukraine, where dozens have died.
Sentencing was postponed until Monday, meaning it will be revealed after Sunday's close of the Sochi Winter Olympics, a prestige project for Putin, who has faced criticism from the West for his treatment of dissenters but says he does not use the courts as a political tool.
The eight were convicted of rioting and assaulting police during an opposition protest on May 6, 2012, the eve of Putin's inauguration to a third term as president.
Two women from protest band Pussy Riot were in the crowd outside, as was Alexei Navalny, an opposition leader who is serving a five-year suspended sentence after a trial last year he said was Kremlin revenge.
Prosecutors asked for prison sentences of five to six years for the defendants, who pleaded not guilty and blame police for clashes that erupted at the rally - part of a series of protests that were the biggest of Putin's long rule but failed to prevent his return to the Kremlin after four years as prime minister.
Former oil tycoon Mikhail Khodorkovsky, who was widely seen as a political prisoner during more than 10 years in jail, said the defendants were victims of a "show trial".
"Almost no one doubts that the verdict will be vindictive and cruel," Khodorkovsky, who was flown out of Russia on the day of his release in December, said in a statement on Thursday.
Activists and relatives said they feared the deadly violence this week in Ukraine, which Russia has blamed on anti-government militants it says have been encouraged by the West, decreased the chances the defendants would be sentenced to time served and walk free.
(Additional reporting by Ian Bateson and Alexei Anishchuk; Writing by Steve Gutterman; Editing by Gareth Jones and John Stonestreet)