MOSCOW (AP) — A Moscow court has sentenced a protester to 2 ½ years in prison for throwing a brick at a riot policeman during an opposition rally earlier this year.

The March 26 rally on Moscow's main street, organized by opposition leader Alexei Navalny, was a rare unauthorized protest against President Vladimir Putin. Rallies were held in dozens of other Russian cities and towns in the biggest outpouring of discontent in years.

A judge at a Moscow court on Thursday found Stanislav Zimovets guilty of using violence against the police, Russian news agencies reported. Prosecutors said Zimovets threw a brick at the policeman, "causing him physical pain."

Two other people have been convicted of attacking policemen at that rally — one sentenced to eight months, another to 1 ½ years in prison.