Even as US-led forces in Iraq made progress against loyalists of militant Shiite cleric Moqtada al-Sadr over the weekend, the insurgency spread from the holy cities of Najaf and Karbala to British-controlled cities of Basra and Amarah in the south.
Analysts say the escalation is evidence that coalition military efforts are squeezing Sadr's Mahdi army, forcing them to fight elsewhere. But at the same time, Sadr - whom the US has vowed to "capture or kill" - is capitalizing on the horror over the Iraq prison scandal to broaden his appeal.
"The wild card is the reports of [American] torture and humiliation," says Amatzia Baram, an Iraq expert at the US Institute of Peace in Washington. "Until that came out, [Sadr] was definitely on the decline. Now he is championing the case of the prisoners.
Moderate and far higher-ranking Shiite clerics have indirectly denounced the anti-American Sadr and his methods, and in Najaf on Friday, one prayer leader asked that he and his militia leave the city altogether.
But Sadr countered with his own firebrand sermon at his home mosque in Kufa, where he rallied his thousands-strong Mahdi army with anti-US vitriol. "What sort of freedom and democracy can we expect from you when you take such joy in torturing Iraqi prisoners?" Sadr asked.
Sunday in the Shiite slums of Baghdad - after US troops mounted an overnight raid to arrest three Sadr aides - the Mahdi army used loudspeakers to warn residents that US forces would be attacked if they came into the district.
"If Sadr dies, there will be 1,000 more Sadrs to take his place," says a Mahdi militiaman. "It's become the Iraqi people's war."
Some 2,500 American troops has tightened the noose around Sadr since launching an offensive last Tuesday that has drawn Sadr fighters away from areas deemed holy by Shiite Muslims.
Sadr supporters opened new fronts against British forces over the weekend, to try to take over parts of Basra and Amarah. Sunday in Amarah, British troops reportedly responded to mortar strikes with helicopters. Those attacks came a day after a Sadr chief said jihad was required to avenge tortured detainees. A reward of $350 was offered for the capture of a British soldier; $150 for killing one.
"There is some pressure on Sadr in Najaf; maybe he's flexing his muscle elsewhere," says Hamid al-Bayati, Iraq's deputy foreign minister, who belongs to a moderate Shiite group. "It's difficult to know who can really influence him."
"The future depends on how we defuse this," says Dr. Bayati. If US forces "go in to capture or kill [Sadr], it will get worse."
US authorities in Iraq have issued an arrest warrant for Sadr, whom they charge with involvement in the murder of a rival pro-US cleric 13 months ago.
On Saturday, US forces dropped leaflets around Najaf, to declare that they would "continue to work with Iraqis to defeat terrorism" after that date. Previous leaflets warned gunmen that continued fighting "will lead to your death. You choose your destiny."
Though Sadr is a junior cleric, he comes from a long line of popular senior ayatollahs who paid with their lives to take on the secular authority and tyranny of Saddam Hussein.
"The Coalition has to tread a very fine line," says a Western adviser to the Coalition Provisional Authority (CPA) in southern Iraq. "Often Iraqis say, 'You must act against these people.' But if you do, they stop you, and ask, 'What are you doing?' "
As the conflict burns on, though, Sadr's own tactics may be harming his standing among Iraqi Shiites, who are tired of the constant political and military skirmishing.
British and Iraqi forces at dawn on Saturday in Amarah cleared buildings that had been used to launch militia attacks, including the local library, labor union, and telecom-ministry office. A raid on the provincial Sadr office yielded four truckloads of ordnance, including surface-to-air missiles. Similarly, on a tip from Iraqi citizens in Diwaniyah, according to the US military, at a girls' school that the Sadr militia had ordered closed two weeks earlier, US and Iraqi forces found 35 mortar rounds, rocket-propelled grenades, and other ordnance.
"Every cache reveals that Sadr hides under the cloak of religion, and has an aggressive military intent," says the CPA adviser. "It is undermining his credibility among Iraqis."
Sadr's brand of open confrontation has won him little popular support in Najaf and Karbala, long bastions of the quieter branch of Shiite Islam in Iraq that follows the example of Grand Ayatollah Ali Sistani, Iraq's preeminent theologian in Najaf. Business has dropped dramatically in both cities because of the unrest, and many blame Sadr.
Even Sadr's Iranian mentor, the hardline Ayatollah Kazem al-Haeri, has made clear his displeasure with Sadr, stating through a spokesman that Sadr is not authorized to make political decisions or wage jihad against coalition forces in the ayatollah's name - the second time in a year that Mr. Haeri has disassociated himself from the junior cleric.
"The ancient Shia way is you never go into an all-out attack; you maneuver to defeat your enemy, without fighting," says Baram. "Sadr is very exceptional in this way. He reminds me of Saddam Hussein - when you count the similarities, your mouth hangs open."
Baram says that Sadr has his own courts, police, detention centers, and torture chambers.
Sadr needs media attention "all the time, like oxygen," says Baram. Another reminder of Mr. Hussein is the identical affectation that some Sadr supporters now add when they mention his name: "May God protect and preserve him."