Kyrgyz President Roza Otunbayeva said on Friday that unnamed forces were seeking a pretext to repeat the violence that killed hundreds of people in the country's ethnically divided south a year ago, according to Reuters. Ethnic Kyrgyz and Uzbeks battled each other last year in and around the cities of Osh and Jalalabad. More than 400 were killed, including many burnt alive in their homes or shot by marksmen, in four days of clashes that began on June 10, 2010. "Today there are forces still willing to earn political capital at the expense of the grief, blood and tears shed by the innocent, to use the nation's tragedy as a means in their struggle for power," Otunbayeva said. "Those seeking a pretext and an opportune moment to split the nation and spark new, bloody clashes are still active." Otunbayeva, who laid flowers at a marble monument in central Osh to commemorate the victims on the first anniversary of the riots, did not specify the nature of these forces. Rights groups Amnesty International and Human Rights Watch warned this week that the failure of Kyrgyzstan's government to punish those responsible for last June's killings heightened the risk of renewed violence. Uzbeks made up three-quarters of casualties and sustained 90 percent of property losses, but were also the main target of ethnically biased investigations, the rights groups said in separate reports. Torture is often used on detainees, they said. "Law enforcement investigations into the June events have routinely been accompanied by allegations of extortion, ill-treatment and torture of detainees," Rupert Colville, spokesman of the United Nations High Commissioner for Human Rights, told a news briefing in Geneva on Friday. A total of 375,000 people fled their homes during the riots, UNHCR, the U.N. refugee agency, said on Friday. About 60,000 people are still scattered across Kyrgyzstan and abroad and another 20,000 are living with host families, it said. Colville said there were serious concerns the fighting could break out again. "Clearly, if discrimination continues against minorities, when they are so closely packed in a very highly populated area, it's obviously a dangerous situation," he said. Instability in Kyrgyzstan, a mainly Muslim nation of 5.3 million, has fuelled tension in ex-Soviet Central Asia, a region where radical Islam stoked by widespread poverty is on the rise. Kyrgyzstan, which borders regional giant China and hosts U.S. and Russian military air bases, saw its president, Kurmanbek Bakiyev, deposed by a violent revolt in April 2010. TENSION IN THE AIR In the ancient city of Osh, whose population of some 500,000 is almost equally divided into Uzbeks and Kyrgyz, bazaars -- an old barometer of tranquillity in Central Asia - are busy. But tension remains, with many houses burnt down in the riots still not restored and tea houses left charred and abandoned. "We hope there is no return to what happened here," said Abdurakhmat Usmanov, an Uzbek aged 71. "Last time, the world community did not react but we hope that, should something occur now, they will turn their attention to us and send in troops." Reinforced police units patrol the streets, wearing bulletproof vests and wielding Kalashnikov submachine guns. Elaman Myrzabek-uulu, a 17-year-old ethnic Kyrgyz member of a 500-strong, unarmed vigilante team helping police keep order in Osh, said he was concerned there were no Uzbeks among them. "Our relations ought to be better. We have not become friendlier to each other since last year," he said. "Uzbeks are not open for contact. They do not trust us, although I aided Uzbeks during the June events." UNHCR said it was hearing repeatedly from different individuals about distrust of the local authorities. "There is still a certain degree of suspicion between communities, and the most affected groups are not yet fully ready for reconciliation," it added. Otunbayeva, who will step down at the end of the year after a new president is elected in October, admitted she had received "numerous complaints about unjust judges and corrupt policemen". She said "purges" would continue in law enforcement bodies and the judiciary.