Two days after the government confronted protesters in clashes that left hundreds dead, the eastern city of Andijon is in a virtual lockdown.
While some gunfire was heard in the city, Andijon resembled a ghost town Monday, with local residents staying off the streets. Armed police stood on most corners, and armored vehicles surrounded the main police station.
The area around the central square, where deadly clashes broke out Friday in protest of government charges of religious extremism against 23 businessmen, was completely sealed off. A seven-story administration building, occupied by protesters during the events, could be seen from a distance to be a charred and blackened hulk.
The violence in the region is the greatest Uzbekistan has seen since gaining independence from the Soviet Union in 1991. If reports of more than 700 deaths since Friday hold true, and if Uzbek forces were behind the killing, as most reports indicate, it would be some of the worst state-inspired bloodshed since China's Tiananmen Square massacre in 1989 - and could threaten the stability of the government in this key Central Asian ally.
Svetlana Artikova, spokeswoman for the prosecutor general's office, said Monday that her office had launched a criminal investigation against those detained on charges of staging riots in Andijan. She refused to comment on the number of people arrested.
Despite the harsh government response to the Andijon uprising, conflict has continued to spread. Saidjahon Zaynabitdinov, head of the local human rights advocacy group Appeal, charged Monday that government troops killed about 200 demonstrators Saturday in Pakhtabad, about 20 miles northeast of Andijon. There was no independent confirmation of his claim.
A UN official said on condition of anonymity that government troops were concentrated Monday near the city of Namangan, a major transport hub in the Fergana Valley. In the border town of Teshiktosh, eight soldiers and three civilians were killed Sunday and hundreds of Uzbeks fled into neighboring Kyrgyzstan, witnesses said.
That violence would have come in the wake of some 500 people reportedly were killed in Andijon - Uzbekistan's fourth-largest city - when government troops put down a prison uprising by alleged Islamic militants and citizens protesting dire economic conditions.
In the border community of Korasuv, an estimated 5,000 people forced authorities to restore a bridge across a river to Kyrgyzstan, whose government was overthrown in March.
Thousands of refugees also converged on a border crossing at the village of Barash, about 30 miles north of Andijon. More than 500 made it to Kyrgyzstan, setting up a tent camp in a field just across the border.
"There is a large population of ethnic Uzbeks living in Kyrgyzstan, so people have relatives and friends there," says Vitaly Naumkin, an expert on Central Asia. "The situation on the Uzbek side of the border in the Ferghana Valley is awful in the best of times, and it's deteriorating badly now. People are terrified of reprisals by the authorities for the unrest."
In Andijon, Gulboxior Turajewa, head of the local branch of an international nongovernmental organization, went to School No. 15 on Saturday, where she saw some 500 bodies laid out. She saw another 100 bodies at the nearby Institute for Technical Instruction.
By Sunday, most of the bodies at the school had been claimed by relatives, she added.
The prison outside of town, where crowds released some 2,000 prisoners Friday morning, looked quiet and there were no signs of fighting other than a bullet-ridden, burned out car.
The violence in Uzbekistan puts the United States in a difficult position because it relies on Karimov's government for an air base in the country and anti-terrorism support.
So far, US authorities have only called on both sides to work out their differences peacefully.
• Fred Weir contributed to this report from Moscow.