President Kurmanbek Bakiyev of Kyrgyzstan is refusing to resign, despite the opposition in his country disolving parliament and setting up what it says is an interim government.
The president has fled the capital and is reported to be in the south of the Central Asian republic.
The opposition, under ex-foreign minister Roza Otunbayeva, says it has taken full power.
The president told BBC Russian he was in southern Kyrgyzstan, but would not disclose the exact location.
Mr Bakiyev said he was the legitimate president and condemned the uprising.
More than 70 people were killed during clashes in the capital, Bishkek, on Wednesday. More gunfire was heard after nightfall on Thursday.
The United States says it has been able to continue limited operations at its airbase in Kyrgyzstan, from where supplies are transported to US forces in Afghanistan.
Russia also has a military base and has sent 150 extra paratroopers there.
Moscow has denied playing any role in the unrest.
Mr Bakiyev came to power in the "Tulip revolution" five years ago.
Ms Otunbayeva said her interim government was fully in control of the country and had appointed new ministers. She said elections would be held in six months.