Five years of stability in Central Asia's most populous state crumbled this week when a series of bomb blasts and shootings killed at least 47 people.
The violence in the capital Tashkent and ancient Silk Road oasis of Bukhara was swiftly blamed on Islamic insurgents by a US-backed government criticised in the West for clamping down on opposition, controlling religion and jailing dissidents.
"Muslims, be watchful," Tashkent's chief Imam, Anvar Haji Tursunov, on Friday told a congregation of several thousand at his mosque just metres away from a market where two explosions from alleged human bombers killed six on Monday.
"The kamikazes are against Allah," he intoned. "If you see people like this around you, we must punish them together."
Police have so far arrested 19 people including four women under suspicion of "involvement in terrorist acts", Prosecutor General Rashid Kadyrov told reporters.
President Islam Karimov has tightly controlled the resurgence of Islam since the collapse of the Soviet Union. His picture hangs in the Imam's office and in the classrooms of a nearby 16th century madrassah or religious school.
"The Uzbek government should stop targeting people for their religious affiliations..."
chief, Central Asia and Europe,
Human Rights Watch
Human Rights Watch said of 11 arrests it had documented, most detainees were former religious prisoners or their relatives who had been "arbitrarily" arrested. It has said the violence is being used as a pretext for a crackdown.
"Detainees held incommunicado in Uzbekistan are in immediate danger of torture," said Rachel Denber, Human Rights Watch Central Asia and Europe chief.
"The Uzbek government should stop targeting people for their religious affiliations and should immediately grant detainees access to family members and lawyers."
Uzbekistan has jailed 7,000 Muslims who do not subscribe to state Islam, human rights groups estimate.
It is the first time since bomb attacks hit Tashkent in 1999, one almost killing Karimov, that the ruling elite's tight grip on power has been shown to be under any remote threat.
The blasts have been low level - often killing only the alleged human bomber - and the choice of targets unspectacular. Extreme poverty, police corruption, and the mass detentions have fuelled resentment.