A leading rights watchdog accused Armenia on Wednesday of conducting "politically motivated" trials over deadly 2008 riots while failing to investigate police culpability.

Ten people were killed when police and protesters clashed in the capital Yerevan after the opposition alleged fraud in a presidential election.

More than 100 people were detained during a state of emergency imposed after the violence, but rights groups and the opposition say the government has done little to investigate allegations of excessive use of force by police and ill-treatment in custody.

New York-based Human Rights Watch said it was clear from many accounts that police made excessive use of force, and that the use of guns appeared to have been indiscriminate or disproportionate. "The Armenian authorities' response to the March 1 events has been one-sided," the group said in a report.

"While they investigated, prosecuted, and convicted dozens of opposition members, sometimes in flawed and politically motivated trials, for organising the demonstration and participating in violent disorder, they have not prosecuted a single representative of the authorities for excessive use of force."

The authorities accused the opposition of trying to overthrow the government after an election won by current President Serzh Sarksyan.

Westerm election monitors said the vote was broadly in line with the country's international commitments but that further improvements were necessary.

More than 50 people received jail sentences over the unrest. A number have since been pardoned by Sarksyan, going some way to placating European rights bodies.

Human Rights Watch said Armenia's public prosecutor should step up efforts to conduct an independent, impartial investigation into police actions and allegations of ill-treatment of detainees. It urged the country to address shortcomings in the electoral process and pervasive public distrust that have left Armenia "stuck in a cycle of uneven contests, fraud, and disputes that more often than not spill onto the streets."

"To the extent that it exists, real political competition is volatile with a permanent risk of violence," the report said.

Reuters