Parts of Kyrgystan's second-largest city were ablaze on Saturday as the death toll rose to 50 in a second day of ethnic conflict, the Central Asian state's worst violence since the president was toppled in April.
The interim government in Kyrgyzstan, which hosts US and Russian military bases, said it was powerless to stop armed gangs from burning down the homes and businesses of ethnic Uzbeks in one part of Osh. Gun battles raged throughout the night.
"Entire streets are on fire," Interior Ministry spokesman Rakhmatillo Akhmedov said. "The situation is very bad. There is no sign of it stopping. Homes have been set ablaze."
Kyrgyzstan, a poor ex-Soviet state of 5.3 million people, declared a state of emergency in Osh and several local rural districts early on Friday after rival ethnic gangs fought each other with guns, iron bars and petrol bombs.
Renewed turmoil in Kyrgyzstan will fuel concern in Russia, the United States and neighbor China. Washington uses an air base at Manas in the north of the country, about 300 km (190 miles) from Osh, to supply its forces in Afghanistan.
A Reuters correspondent in Osh said gun battles had taken place through the night in an Uzbek neighborhood. Gas was shut off to Osh and some neighborhoods have no electricity.
Ethnic Uzbeks were fleeing to the border, said Farid Niyazov, spokesman for the interim Kyrgyz government.
One witness said some women and children had made it across to the Uzbek town of Marhamat, 60 km (38 miles) from Osh, and camps had been set up for those without family in Uzbekistan.
A spokeswoman for the Kyrgyz Health Ministry said at least 50 people had been killed and 663 wounded in the violence, which is taking place in the southerly power base of former president Kurmanbek Bakiyev, deposed in April by a popular revolt.
"Everywhere is burning: Uzbek homes, restaurants and cafes. The whole town is covered in smoke," local human rights worker Dilmurad Ishanov, an ethnic Uzbek, said by telephone from Osh.
"We don't need the Kyrgyz authorities. We need Russia. We need troops. We need help."
The interim government, led by Roza Otunbayeva, sent in troops and armored vehicles and declared a night-time curfew in Osh. But Niyazov said law enforcement bodies had been unable to quell the violence and would require reinforcement.
Kyrgyzstan, which won independence with the collapse of the Soviet Union in 1991, has been in turmoil since the revolt that toppled Bakiyev on April 7, kindling fears of civil war.
Supporters of Bakiyev, now in exile in Belarus, briefly seized government buildings in the south on May 13, defying central authorities in Bishkek.
While these clashes were motivated by politics, the latest violence has stoked fears of a repeat of the bloodshed in 1990, when hundreds of people were killed in clashes between Kyrgyz and Uzbeks in Osh.
Ethnic unrest is a concern in the Fergana Valley, where Kyrgyzstan and Uzbekistan intertwine. While Uzbeks make up 14.5 percent of the total Kyrgyz population, the two groups are split roughly equally in the Osh region.
On May 19, two people were killed and 74 wounded in clashes between Kyrgyz and Uzbeks in the city of Jalalabad. On the same day, Otunbayeva said she would rule the country until the end of 2011, scrapping plans for presidential polls in October.
Her interim government, which plans a national referendum on June 27 to vote on changes to the constitution, now faces a major test in trying to reassert control in Osh, said Lilit Gevorgyan, analyst at IHS Global Insight:
"The explosive combination of a counter-revolution and an ethnic conflict poses the greatest threat to the future of the Kyrgyz revolution."