Uzbek troops have opened fire on thousands of demonstrators in the eastern city of Andijon killing at least one person.
The protesters have taken over several government buildings and some are demanding that President Islam Karimov resign.
Mr. Karimov is reported en route to Andijon, after an overnight prison break there sparked earlier clashes that left at least nine dead and 34 injured.
Officials say the violence began today-Friday after rebels stormed the prison to free 23 Islamic businessmen on trial on charges of forming an extremist group.
Uzbek officials say talks are underway at the prison with rebels, who have taken at least 10 police hostage and freed about 2,000 prisoners.
Meanwhile, Israel has raised the level of alert at its embassies around the world after security guards, in a separate incident, killed a man carrying a fake bomb outside the Israeli embassy in the Uzbek capital, Tashkent.
Information for this report is provided by AP, AFP and Reuters.