Russian prosecutors say they will extradite to Uzbekistan 13 people facing terrorism charges over the 13 May 2005 Andijan crackdown.
It is not clear how many people died in Andijan on 13 May 2005
The men are suspected of crimes including incitement of extremist acts and murder, a Russian official said.
But rights groups say the cases against the men, who they describe as refugees, are fabricated.
Uzbekistan says 187 people died in Andijan when troops shot civilians, but witnesses put the figure much higher.
The Uzbek government says soldiers were eliminating a dangerous group of Islamic extremists, but witnesses say troops opened fire on a crowd of anti-government demonstrators in the town square.
The Russian authorities say they have received a guarantee from Uzbekistan that the 13 men, all ethnic Uzbeks, will not be tortured or sentenced to death.
"The Uzbek side guarantees that the extradited persons - in accordance with the norms of international law and national legislation - will be given all the opportunities for defence, including lawyers' assistance," a Russian official told Itar-Tass news agency.
But rights groups said they feared for the men's safety.
"These people are accused in fabricated cases and could face gigantic prison terms in Uzbekistan; several could even face the death penalty," Yelena Ryabinina of the Civil Assistance rights group told Reuters news agency.
The men have been held in the city of Ivanovo, some 300 km (180 miles) east of Moscow, since their arrest in June 2005.
Since May 2005, the Uzbek authorities have jailed dozens of people on charges of Islamic extremism, observers say.
They have also put pressure on neighbouring Kyrgyzstan to return people sheltering there who are accused of extremism.
Western nations have repeatedly called for a probe into the killings in Andijan, but the Russian authorities have supported Uzbekistan in what it calls a fight against terrorism.