The UN says that the number of people displaced by unrest in southern Kyrgyzstan has reached 400,000.
About 300,000 people have fled their homes, while another 75,000-100,000 people - not counting children - are thought to have taken refuge in Uzbekistan.
The Red Cross (ICRC) has described the situation as an "immense crisis".
Some aid has begun to arrive in the region, but the ICRC says refugees are running short of basic supplies.
People have been leaving after violence between Kyrgyz and ethnic Uzbeks last week, in which at least 191 were killed. Some observers have said the death toll is higher.
The latest UN Humanitarian Office figure exceeds previous estimates of 250,000-275,000 displaced.
