U.S. Army and Marine units thrust through the center of the insurgent stronghold of Fallujah on Tuesday, fighting bands of guerrillas in the streets and conducting house-to-house searches on the second day of a major offensive to retake the city from Islamic militants.
A total of 14 Americans have been killed in the past two days across Iraq, including three killed in Fallujah on Tuesday and 11 others who died Monday, most of them as guerrillas launched a wave of attacks in Baghdad and southwest of Fallujah, a senior Pentagon official said.
The 11 deaths were the highest one-day U.S. toll in more than six months.
As fighting raged in Fallujah, Prime Minister Ayad Allawi declared a nighttime curfew in Baghdad and its surroundings, the first curfew in the capital for a year, a day after a string of insurgent attacks in the city killed nine Iraqis and wounded more than 80.
Anger grew among Iraq's Sunni Muslim majority over the assault on the mainly Sunni city of Fallujah. A powerful group of clerics called for a boycott of January elections.
U.S. and Iraqi forces launched the invasion of Fallujah to restore government control in the insurgents' strongest bastion ahead of the elections. But the assault risks alienating Sunnis, and if they boycott, the vote's legitimacy could be deeply undermined.
In Fallujah, heavy street clashes were raging in northern neighborhoods. By midday, U.S. armored units had made their way to the highway running east-west through the city's center and crossed over into the southern part of Fallujah, a major milestone.
Still, the military reported lighter-than-expected resistance in Jolan, a warren of alleyways in northwestern Fallujah where guerillas were believed to be at their strongest.
That could be a sign that insurgents left the city before the operation started or that the troops have not yet reached the center location to which the resistance has fallen back, Pentagon officials said in Washington.
An estimated 6,000 U.S. troops and 2,000 allied Iraqi soldiers invaded the city from the north Monday night in a quick, powerful start to an offensive aimed at re-establishing government control ahead of the January elections. The guerrillas fought off a bloody Marine offensive against the city in April.
Allawi called on Fallujah's fighters to lay down their weapons to spare the city and allow government forces to take control, "The political solution is possible even if military operations are ongoing," his spokesman said.
In Fallujah's urban battles Tuesday, small bands of guerrillas, fewer than 20, were engaging U.S. troops, then falling back in the face of overwhelming fire from American tanks, 20mm cannons and heavy machine guns, said Time magazine reporter Michael Ware, embedded with troops. Ware reported that there appeared to be no civilians in the area he was in.
On one thoroughfare in the city, U.S. troops traded fire with gunmen holed up in a row of houses about 100 yards away. An American gunner on an armored vehicle let loose with his machine gun, grinding the upper part of a small building to rubble.
Elsewhere, witnesses reported seeing at least two American tanks engulfed in flames. A Kiowa helicopter flying over southeast Fallujah took groundfire, injuring the pilot, but he managed to return to the U.S. base.
The once constant thunder of artillery barrages was halted, since so many troops are moving inside the city's narrow streets. U.S. and Iraqi forces surrounded a mosque inside the city that was used as arms depot and insurgent meeting point, the BBC reported.
Col. Michael Formica, commander of the 1st Cavalry Division's 2nd Brigade, said Tuesday that a security cordon around the city will be tightened to ensure insurgents dressed in civilian clothing don't slip out.
"My concern now is only one, not to allow any enemy to escape. As we tighten the noose around him, he will move to escape to fight another day. I do not want these guys to get out of here. I want them killed or captured as they flee," he said.