Updated

A Russian man who participated in an anti-Kremlin protest has been convicted of "calling for mass riots" and sent for forced psychiatric treatment.

Mikhail Kosenko was one of 28 people arrested after clashes broke out between demonstrators and police at a protest on May, 6, 2012, the eve of President Vladimir Putin's inauguration for a third term.

The prosecution claimed that Kosenko used violence against policemen, but said a psychiatric examination found he "wasn't able to realize the public danger of his actions" due to a "chronic mental disorder."

Human rights activists assailed Tuesday's ruling, describing it as the return of the Soviet practice of using punitive psychiatry against dissidents.

After returning to the presidency last year, Putin has cracked down on street protests and other demonstrations of dissent.