"I direct my speech to my enemy Bush and I tell him that if your excuse was that you are fighting Saddam, then this thing is a past and now you are fighting the entire Iraqi people," Moqtada al-Sadr said in a sermon, delivered by one of his deputies at the Imam Ali Shrine, Shiite Islam's holiest site, in Najaf.
U.S. troops regained control of the city of Kut, which had fallen to al-Sadr's rebels earlier in the week. But the cleric's army kept control of Kufa and the center of the nearby holy city of Najaf, despite a vow by U.S. commanders Wednesday to crush the militia.
Both U.S. casualties occurred in Baghdad, one when insurgents attacked a convoy transporting fuel at the capital's main western entrance, the military said. An Iraqi driver in the convoy was also killed. The other soldier was killed by a roadside bomb. The deaths brought the U.S. toll in Iraq to 644.
U.S. troops were patrolling the capital streets with loudspeakers warning people that anyone caught on the street with a gun will be shot on sight, CBS News Correspondent Kimberly Dozier reports.
In the same square where a statue of Saddam was toppled a year ago, a poster of al-Sadr was attached to an unfinished bronze monument at the site. U.S. soldiers climbed up and tore it down.
"We are at a moment of testing in Iraq," White House communications director Dan Bartlett told the CBS News Early Show. "The reason is because the enemies of democracy know the stakes are high."
In major developments:
The heavy siege of Fallujah, a bastion of anti-U.S. Sunni guerrillas, has angered even pro-U.S. Iraqi officials.
"These operations were a mass punishment for the people of Fallujah," Adnan Pachachi, a senior member of the U.S.-appointed Governing Council, told Al-Arabiya TV. "It was not right to punish all the people of Fallujah and we consider these operations by the Americans unacceptable and illegal."
Bremer said in a statement that the halt in operations also aimed to allow humanitarian supplies into the city and "allow residents of Fallujah to tend to wounded and dead."
Five days of heavy fighting using tanks, warplanes and helicopter gunships in residential areas of the city of 200,000 has killed more than 280 Iraqis and at least four Marines.
Insurgents, armed with automatic weapons and rocket-propelled grenades, have put up stiff resistance, but Marines have said they are winning the battle, holding at one point around a quarter of the city.
Scores of Fallujah residents tried to leave the city during the brief pause in fighting, said Byrne. Troops used loud speakers overnight to tell people that old men, women and children would be allowed to leave, but not "military-age men."
The newly invigorated insurgency — Sunni rebels in the west and Shiite guerrillas in central and southern regions — further threatens shaky Iraqi security as the U.S.-led Coalition Provisional Authority prepares to hand sovereignty to an Iraqi government on June 30.
U.S. forces moved into Kut two days after Ukrainian forces abandoned the city in the face of heavy fighting with al-Sadr followers. Police in several cities have also abandoned their stations or stood aside as the gunmen roam the streets — raising concerns over the performance and loyalty of a force U.S. administrators are counting on to keep security in the future Iraq.
U.S. forces that swept into Kut before dawn seized police stations, forcing out both Iraqi police and militiamen and confiscating all police weapons stores throughout the city, witnesses said. There was little resistance.
A U.S. helicopter struck al-Sadr's main office in Kut, killing two people, witnesses said. During the day, Americans were patrolling the streets.
Coalition forces also have moved in to block the road between Kufa and Najaf, a senior aide to al-Sadr, Sheik Qays al-Khaz'ali, told The Associated Press.
Al-Sadr followers attacked a government building where U.S. troops are based in Baqouba, north of Baghdad, after Friday prayers. A tank was seen burning. Also, a mortar hit a house near a police station, killing two people, police said.
U.S. troops also came under heavy attack in Muqdadiyah, 55 miles northeast of Baghdad. Up to 80 insurgents ambushed a U.S. patrol late Thursday, prompting an overnight battle. At least three insurgents were killed and up to 20 wounded, said Lt. Col. Peter A. Newell.