|Unidentified armed men speak with local residents in downtown Andijan|
Uzbek foreign ministry officials say negotiations are under way with rebels at the prison, who have taken at least 10 policemen hostage, after earlier freeing some 2,000 prisoners.
Details are sketchy as the situation remains fluid and there are conflicting reports over who is in control, the government or rebels. But it is clearly the worst outbreak of violence in Uzbekistan since a spate of bombings in the capital, Tashkent, last year, blamed on Islamic separatists.
Latest reports say the rebels in Andijan, in Uzbekistan's volatile Ferghana Valley, have asked for Russia to mediate. In remarks broadcast on Russian television, Foreign Minister Sergei Lavrov ruled out any direct involvement for now.
Mr. Lavrov says the issue is for local Uzbek authorities to handle, but he said Russia, which has foreign nationals in the region, would watch the situation closely.
The head of the Russian Duma's State Committee for International Affairs, Konstantin Kosachev, has also expressed serious concern. But he says it is too early to tell whether the unrest signals broader public discontent that could spark a possible revolution or coup.
Mr. Kosachev says there are two current interpretations of the events. He says one view is that the violence is a sporadic disturbance that will likely be brought under control. But according to Mr. Kosachev, the second view is that the unrest is just the beginning of more violence that could spread across Central Asia.
Perhaps fearing that scenario, neighboring Kyrgyzstan and Kazkahstan closed their borders until further notice. Tajikistan's border with Uzbekistan remains open, but amid heightened security measures.
The violence comes amid anger over a high-profile trial of more than 20 Muslim business owners for alleged Islamic extremism. The businessmen deny the charges and say they are being singled out for holding religious views other than the state-sponsored Islam espoused by Mr. Karimov's regime.
President Karimov has defended his hard-line stance, saying he is fighting the rise of militant Islam.
In a separate incident in the Uzbek capital, Tashkent, police have shot and killed a man who approached the Israeli embassy in a suspicious manner and ignored orders to stop. Authorities initially described the man as a suspected suicide bomber, but local police were later quoted as saying he was wearing what looked like an explosives belt.
Suicide bombers targeted the Israeli and U.S. embassies in Tashkent last year, killing two, in an attack claimed by the Islamic Movement of Uzbekistan.