Two human rights groups have concluded that Kyrgyzstan's failure to prosecute those responsible for last year's deadly ethnic riots could ignite new violence.

A year ago this month, about 470 people were killed, thousands injured and hundred of thousands displaced as ethnic Kyrgyz and Uzbeks clashed in southern Kyrgyzstan. Now, Amnesty International and Human Rights Watch said in separate reports Wednesday that the Kyrgyz government discriminated against the Uzbek minority during the five days of unrest and during the investigation and trials that followed.

Both rights groups said that most of the victims of the rioting were Uzbeks, a minority in the central Asian nation of 5.5 million people. Yet most of those detained — about 85 percent — were also Uzbeks, including 115 of the 124 charged with murder.

Human Rights Watch said the government conducted “profoundly flawed” investigations and trials mainly affecting the Uzbek minority. The New York-based group said the government's actions “undermine efforts to promote reconciliation” and could lead to more outbursts.

London-based Amnesty International said “ethnic bias and corruption” were at the root of the “pervading impunity” in Kyrgyzstan. Human Rights Watch said there are “strong indications” that some military and police units “knowingly or unwittingly facilitated” the attacks on the Uzbek neighborhoods.

The rioting last year occurred as a provisional government struggled to gain a foothold after former President Kurmanbek Bakiyev was ousted in a bloody uprising in April. Uzbeks supported the interim government, while many Kyrgyz in the south supported the toppled leader.