http://www.nytimes.com/aponline/201...son8.nytimes.com/pages/world/asia/index.jsonp OSH, Kyrgyzstan (AP) -- An estimated 400,000 people -- nearly one-twelfth the population -- have fled their homes to escape Kyrgyzstan's ethnic violence, the U.N. said Thursday as throngs of refugees huddled in grim camps along the Uzbekistan border without adequate food or water. That figure represents half the roughly 800,000 ethnic Uzbeks who lived in Kyrgyzstan's south before Central Asia's worst ethnic violence in decades erupted there last week. More than 200 people -- possibly many more -- have been killed, and Uzbeks have been all but purged from some parts of the south. Ethnic Uzbeks on Thursday accused security forces of standing by or even helping ethnic-majority Kyrgyz mobs as they slaughtered people and burned down neighborhoods. Col. Iskander Ikramov, the chief of the Kyrgyz military in the south, rejected allegations of troop involvement in the riots but said the army didn't interfere in the conflict because it was not supposed to play the role of a police force. The military and police set up roadblocks and began patrols this week after the worst violence was over. Uzbeks interviewed by Associated Press journalists in Osh, the country's second-largest city, said that on one street alone, ethnic Kyrgyz men sexually assaulted and beat more than 10 Uzbek women and girls, including some pregnant women and children as young as 12. Matlyuba Akramova showed journalists a 16-year-old relative who appeared to be in a state of shock, and said she had been hiding in the attic as Kyrgyz mobs beat her father in their home in the Cheryomushki neighborhood. Akramova said that when the girl came downstairs to bandage her father's head, another group of attackers sexually assaulted her in front of him. ''What they did to her -- even animals wouldn't do that,'' Akramova said. ''She lost consciousness when they started beating her on the back with feet.'' Human Rights Watch researcher Anna Neistat, who is investigating the violence in Osh, said it was difficult to say how many rapes occurred. ''I just documented at least one case where I spoke to the woman who was raped,'' she said. ''There are several other women in the very same location, so by now I can say with confidence that cases like this did happen. The question is the scale.'' Members of the Kyrgyz community have denied accusations of brutality and have accused Uzbeks of raping Kyrgyz women. Eyewitnesses and experts say many Kyrgyz were killed in the unrest, but most victims appear to have been Uzbeks, traditional farmers and traders who speak a different Turkic language and have been more prosperous than the Kyrgyz, who come from a nomadic tradition. Odinama Matkadyrovna, an Uzbek doctor in Osh, said there were probably more rapes than have been reported, but many victims were reluctant to speak out about their experience. ''Our mentality is such that they conceal (cases of rape),'' she told the Associated Press Television News. U.N. Humanitarian Office spokeswoman Elisabeth Byrs said an estimated 400,000 people have been driven from their homes. About 100,000 refugees are in neighboring Uzbekistan, while some 300,000 displaced people remain inside Kyrgyzstan, a nation of 5.3 million. The last official estimate of refugees who fled the country was 75,000. No number of internally displaced was previously available. The U.N. High Commissioner for Refugees reported that at least 40,000 of the internally displaced need shelter, but many have been taken in by family or other people. Kyrgyzstan's interim government has accused the deposed president of igniting long-standing ethnic tensions by sending gunmen in ski masks to shoot both Kyrgyz and Uzbeks. The government, which overthrew President Kurmanbek Bakiyev in April, accuses the former leader of deep corruption and says that he and his supporters were attempting to shake official control of the south and reassert their grip on the main hub for Afghan heroin trade in the area. Bakiyev, speaking from his self-proclaimed exile in Belarus, has denied involvement. Ole Solvang, a Human Rights Watch researcher investigating the violence in Osh, said he saw soldiers fail to protect residents, and that many witnesses said the military went a step further and helped the rioters. Solvang said Kyrgyz troops were standing just about 200 yards (some 200 meters) from the Cheryomushki neighborhood when the looting and killings started but didn't interfere. ''This is an extreme failure on the part of the government to intervene and protect these people'', he told APTN. Khasan Rakhimov, a resident of Cheryomushki, said soldiers drove an armored personnel carrier into the area and cleared the way for Kyrgyz attackers. ''They shot at all who put up resistance,'' he said of the troops. An uneasy calm enforced by checkpoints and military patrols slowly returned to the center of Osh on Thursday. In Uzbek areas that were not totally cleared out, residents who stayed behind, mostly men, had barricaded themselves into their neighborhoods, felling trees and piling up old cars on the streets. Many Uzbek men said they have lost all faith in the interim government and don't want their relatives to return soon. ''Until we have a 100 percent guarantee of safety, nobody will come back,'' said Ilkhom Rakhimov, a resident of Osh's Sharq district. ''I don't think that will happen any earlier than three months from now.'' Small groups of ethnic Uzbeks, including an elderly invalid in a wheelchair, carefully made their way into Uzbekistan through a small hole in a barbed wire fence marking the border Thursday under the gaze of Uzbek soldiers. Many more were assembled on the Kyrgyz side hoping vainly to follow them. The United Nations Office for the Coordination of Humanitarian Affairs said that Uzbek authorities set up dozens of camps for refugees in three border provinces and made some 70 schools available for sheltering them. The vast majority of the refugees are women, children and elderly people and over 350 pregnant women have been registered so far. The U.N. High Commissioner for Refugees on Wednesday sent two flights to Uzbekistan to deliver relief supplies to the Andijan area where most of the refugees are located, and other U.N. organizations also have provided assistance. Many of the thousands of refugees to have crossed into Uzbekistan said they are afraid to return to Osh, a city with a population of more than 1.1 million together with nearby areas. Many would have nowhere to live if they returned. ''My house is not there anymore, it is burnt down,'' said Khafiza Eiganberdiyeva, 87, who is among 20,000 refugees in a camp set up near Yor Kishlok, three miles (five kilometers) from the Uzbek-Kyrgyz border. Melis Kamilov, a baker who had fled to the border with his wife and five children, said his family lost hope after supplies on the border ran out, and returned out of desperation only to see their home turned to rubble. ''Is there any difference where to die? There is no food, no water, no humanitarian aid,'' the 36-year-old said. ''I am an Uzbek. Is that a crime?'' More than 1 million Uzbeks who lived in Kyrgyzstan before the crisis had few representatives in power and pushed for broader political and cultural rights. About 800,000 of them resided in the south, rivaling Kyrgyz in numbers in Osh and the nearby town of Jalal-Abad. Both ethnic groups are predominantly Sunni Muslim. The deputy head of the provisional government, Azimbek Beknazarov, put the official death toll on both sides at 223, but others said the figure could be significantly higher. Violence has been limited to the south, but Beknazarov said Thursday that the interim authorities fear that Bakiyev's clan also could try to foment unrest in the northern part of the country, including the capital, Bishkek. The government strengthened roadblocks on all entrances into Bishkek and tightened security in prisons to prevent turmoil. -------- Associated Press writers Sergei Grits in Osh, Yuras Karmanau and Leila Saralayeva in Bishkek, Kyrgyzstan, and Eliane Engeler in Geneva contributed to this report.