HRW regional director Holly Cartner said the Uzbek government's attempt to cover up the truth about Andijon now extends into the courtroom itself.
She said the authorities claim to be conducting fair trials, but in fact are withholding all information about the proceedings and denying access to observers.
Earlier this month, 15 men were sentenced to up to 20 years in jail for organizing the revolt. Rights groups criticized those proceedings as a show trial.
Rights groups and witnesses say hundreds of people, mostly civilians, died in the government crackdown in Andijon. The government says 187 people died, mostly militants, police, and soldiers.