Morocco's military trial and imprisonment of 25 Sahrawis, nine of them for life, violated international law, Human Rights Watch charged on Monday, calling on Rabat to either free or retry the defendants in a civilian court.
The New York-based rights watchdog said the military tribunal rejected defense demands to investigate the allegations by the accused that police had tortured them and forced them to sign statements they had not read.
"Time and again, we have seen Moroccan prosecutors appear at politically sensitive trials not with physical or witness evidence establishing the guilt of defendants, but mere confessions obtained under questionable circumstances," HRW's regional director Sarah Leah Whitson said in a statement.
Morocco's officials were not immediately available for comment.
On February 17, the military court in Rabat convicted the 25 men, all of them civilians, over deadly violence in the Western Sahara in November 2010, when the authorities moved to dismantle the Gdim Izik camp where thousands of Sahrawis were living.
Eleven security force agents and two Sahrawi civilians were killed in the clashes sparked by the intervention, which spread to the nearby city of Laayoune, where businesses and public buildings were looted and torched.
The court charged the defendants with intentional lethal attacks against the police, or complicity in those crimes, and sentenced nine of them to life imprisonment, with 14 others given prison sentences ranging from 14 to 20 years.
Most of the defendants had already spent more than two years in pre-trial custody, where they were allegedly tortured and made to sign confessions they had not read, which appeared to be the primary evidence against them, HRW said.
"Morocco should free the convicted Sahrawis or grant them a new and fair trial before a civilian court," said the watchdog, adding that trying civilians in a military court "contravenes a basic norm of international law."
Amnesty International has also condemned the military trial and said torture claims should be probed.
The Western Sahara is a highly sensitive subject in Morocco, which annexed the former Spanish colony in 1975 in a move not recognised by the international community.
Polisario Front separatists insist on the right of the Sahrawi people to a referendum on self-determination, demands rejected by Morocco, which proposes broad autonomy under its sovereignty for the disputed territory.