Kyrgyzstan's interim government has extended a state of emergency in the southern city of Osh and nearby towns and villages following more than a week of deadly clashes between ethnic Uzbeks and Kyrgyz.
The emergency, imposed on June 11 amid deadly fighting, was due to expire on Sunday, but will last until June 25, the government announced.
The announcement came as residents of Osh said they were bracing for fresh violence after security forces started to pull down Uzbek barricades set up during riots last week.
Robin Forestier-Walker, Al Jazeera's correspondent in the capital, Bishkek, said that while there is talk of things getting back to normal, calm has only returned to some places.
"We are hearing that some barricades are still in position, which means that members of the Uzbek community ... fear further attacks," our correspondent said.
"And there is a trust factor - the Kyrgyz government and its military will have to assure the Uzbek communities that they are safe."
Lack of trust
Thousands of ethnic Uzbeks massed on the border of Kyrgyzstan and Uzbekistan are refusing to return to their homes in southern Kyrgyzstan.
The Associated Press news agency reported that Kyrgyz troops entered the border village of Suratash early on Sunday, trying to reassure refugees it was safe to go home.
The refugees declined, saying they feared for their lives and did not trust Kyrgyz authorities to provide protection.
"We are hearing more and more about assaults against ethnic Uzbeks who are trying to travel around. There's concern now, probably among the interim government too, that they have control over their own forces," Forestier-Walker said.
While the official death toll from the clashes is around 200 people, Roza Otunbayeva, the Kyrgyz interim leader, said on Friday that it could be 10-times more than that.
Victims of the unrest say the violence was a brutal and orchestrated campaign by armed groups of ethnic Kyrgyz targeting Uzbeks, who make up 14 per cent of Kyrgyzstan's population of 5.3 million.
The UN has said the unrest appeared to have been orchestrated, but has stopped short of assigning blame.
A top US envoy called on Saturday for an independent investigation into the violence.
After meeting with Kyrgyzstan's acting government, Robert Blake, the US assistant secretary of state for South and Central Asian affairs, said he had been promised by authorities that they would investigate the causes of the violence.
"Such an investigation should be complemented by an international investigation by a credible international body," Blake said on Saturday.
"Is it important for the provisional government to establish an atmosphere of trust and security so the refugees in Uzbekistan and the internally displaced persons in Kyrgyzstan can feel confident that they can return to their homes."
The call for a probe came as Kyrgyzstan prosecutors charged Azimzhan Askarov, the head of a prominent human rights group, with inciting ethnic hatred.
Askarov was charged for shooting a video of unarmed Uzbeks gathering to defend their town during the attacks.
Askarov had accused the military of complicity in the bloody rampages that sent hundreds of thousands of Uzbeks fleeing for their lives.
Tursunbek Akun, the country's rights ombudsman, insisted the charges against Askarov were fabricated, and activists in the capital, Bishkek, demonstrated in front of UN offices to demand his release.
Appeal for aid
Amid the unrest, the World Food Programme said on Saturday that it would step-up its aid to the region after officials and aid agencies said the clashes had affected up to one million people, including 300,000 displaced in Kyrgyzstan and 100,000 who have fled to neighbouring Uzbekistan.
"With a huge number of people displaced by the conflict, and thousands more trapped without food, water or supplies, there's not a moment to lose," Josette Sheeran, the UN agency's executive director, said in a statement.
Ban Ki-moon, the UN secretary-general, said on Friday that the world body was launching a $71 million humanitarian appeal for Kyrgyzstan and that a separate appeal for Uzbekistan would be launched next week.
Kyrgyz authorities say the violence was sparked by supporters of ex-president Kurmanbek Bakiyev, who was toppled in April amid accusations of corruption.
Bakiyev, speaking from self-proclaimed exile in Belarus, has denied any involvement.