Roza Otunbayeva, the Kyrgyz interim leader, had earlier in the day called on Moscow to send troops to control the fighting between ethnic Kyrgyz and Uzbek groups in Osh, the country's second-biggest city.
The interim government, which seized power after anti-government protests toppled the government of Kurmanbek Bakiyev in April, said it was powerless to stop armed gangs from burning down the homes and businesses of ethnic Uzbeks in Osh.
"Since yesterday [Friday], the situation has gotten out of control. We need outside military forces to halt the situation," Otunbayeva, an ethnic Kyrgyz, said.
"We have appealed to Russia for help and I have already signed such a letter for [Russian] President Dmitry Medvedev."
Russia would offer humanitarian assistance and help evacuate the injured in Osh, Timakova, the spokeswoman for Medvedev, said.
She said Russia would conduct consultations with other member nations of the Collective Security Treaty Organisation on Monday on the possibility of sending its peacekeepers to Kyrgyzstan.
The interim government has deployed troops and armoured vehicles and declared a night-time curfew in Osh, and Otunbayeva said more reinforcements would be sent.
She also said her government had decided to open Kyrgyzstan's border with Uzbekistan to allow ethnic Uzbeks to escape the violence.
Al Jazeera's Robin Forestier-Walker, reporting the border on Saturday evening, said thousands of ethnic Uzbeks, mostly women and children, were fleeing their homes.
"We estimate up to 10,000 people have crossed today," he said.
"Unfortunately, nobody is expecting the guns to fall silent just yet. The violence really has continued unabaited for the last 48 hours."
Our correspondent said there was suspicion that the number of deaths in the unrest was actually higher than the latest reported toll, because many people had been unable to get medical assistance.
"The health ministry has itself admitted that they're struggling with the number of people dead and injured," he said.
Of Kyrgyzstan's 5.3 million population, ethnic Kyrgyz make up 70 per cent, Uzbeks 15 per cent and Russians 8 per cent.
Kyrgyzstan has been in turmoil since the revolt that toppled Bakiyev, who is in exile in Belarus.
Political tensions between the agricultural south and the north of the former Soviet republic exist alongside ethnic and clan rivalries.