Uzbek troops stormed a state building held by rebels who had broken comrades out of prison and led anti-government protests that left at least 10 dead.
Rebels led thousands in protests against what they said was the authoritarian rule of President Islam Karimov after seizing the building in Andizhan, a town in Uzbekistan's Ferghana Valley that the government says is home to Muslim extremists.
Troops then opened fire on a square in Andizhan where protesters had massed and stormed the building. By evening, a government source said the building had been taken back but declined to comment on the number of casualties.
Uzbekistan, a Central Asian country bordering Afghanistan, was quick to offer the United States an airbase after the September 11 attacks and has become a key ally in Washington's war on terrorism. But Mr Karimov, in power since the country won independence from the Soviet Union in 1991, has been widely criticised by the West for human rights abuses.
Rights groups say there are at least 6,000 religious and political prisoners in Uzbekistan, where only state-sponsored Islam is allowed. Peaceful protests broke out in Andizhan earlier this week to demand the release of 23 Muslim businessmen, who one rights group said were facing trumped-up charges of religious extremism.
In Washington, White House spokesman Scott McClellan urged the Uzbek government and demonstrators to show restraint. The European Union blamed Karimov's government for the violent protests.