FALLUJAH, Iraq - The battle for Fallujah, the most significant offensive in Iraq since the invasion that toppled Saddam Hussein 20 months ago, began in earnest last night as 10,000 U.S. troops and more than 1,000 Iraqi soldiers attacked the insurgent stronghold in a long-planned assault aimed at ending guerrilla control of the city.
The attack began just past nightfall on the heels of U.S. airstrikes and artillery fire that started Sunday. The main line of assault was to the north of Fallujah, where two Marine-Army combat teams of more than 3,000 men each pressed the offensive in a chilling downpour.
Marines entering from the northeastern Askari neighborhood met heavy resistance as insurgents fired mortars and rocket-propelled grenades. The soldiers encountered many bombs and booby traps.
At a mosque, a cleric exhorted militants to fight back. "God is greatest, oh martyrs!" he shouted over loudspeakers. "Rise up mujahedeen!"
Waiting at a traffic circle for orders to advance further, Marine Staff Sgt. Dennis Nash said: "The most important thing is that we gained a foothold in Fallujah and we didn't experience casualties. From here on out, it's a house-to-house fight."
Army Gen. George W. Casey, the top U.S. military commander in Iraq, said there would likely be a "major confrontation" as an estimated 3,000 insurgents fall back into the center of the city in the face of the American push.
Military experts said the battle could last days or weeks. Defense Secretary Donald H. Rumsfeld said the purpose of the attack was to tame the city and end the battle there. "Every effort has been made to persuade the criminals running roughshod over Fallujah to reach a political solution, but they've chosen the path of violence," he said at the Pentagon.
Yet, even if the insurgents are defeated in Fallujah, U.S. officials expect that rebels will regroup in other cities.
"This will not be the last use of force to rid Iraq of the former regime elements and the foreign fighters who do not want Iraq to be successful," said Air Force Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff. "If there were a silver bullet, we'd have shot that a long time ago."
The attack was approved by interim Iraqi Prime Minister Ayad Allawi, who declared a 24-hour curfew in Fallujah starting at 6 p.m. as the majority of the 10,000 U.S. troops massed outside the city began to enter.
All roads into Fallujah and nearby Ramadi were closed, and the standing order for American troops was to kill anyone carrying a weapon. Roads to neighboring Jordan and Syria were shut, and all commercial flights into the country were canceled for the next two days.
The insurgents "think Iraq now is weak, but I warn them ... that hours of seriousness have begun," Allawi said at a news conference in Baghdad. "I will never permit anyone to inflict harm on the Iraqi people, whether they are foreign terrorists or Saddam loyalists."
The push to retake Fallujah comes less than three months before Iraq is to hold elections to choose a National Assembly. Unless security is restored, it will be difficult to persuade Iraqis to vote or run for office.
Allawi said he would pursue similar campaigns in all Iraqi cities where insurgents threaten to disrupt the political process.
As Allawi spoke, sniper teams and other advance parties in Fallujah called in air and artillery strikes. Plumes of smoke rose above the city as it was battered throughout the morning and afternoon.
Fallujah resident Adnan Mohammed Falluji, 37, an engineer reached last night by phone, said the bombing had gone on all day. "They were bombing both sides of the city with airplanes and artillery. Then the tanks started to bomb the center of the city," he said.
Dr. Hamid Mohammed, speaking from a makeshift clinic that is serving residents after U.S. and Iraqi forces took over Fallujah General Hospital early yesterday, said 15 dead and 20 injured had been brought there, including women and children.
Despite being urged to leave the city, up to 150,000 residents may remain in Fallujah. In a visit yesterday with Iraqi troops accompanying the Americans, Allawi urged soldiers to try to avoid civilian casualties. He also urged Iraqi national guardsmen to avenge the deaths of 49 of their colleagues executed last week by insurgents in Baqouba.
A guardsmen replied: "We will slaughter them like chickens."
Later, Capt. Talib Itbi, 33, said the Iraqi troops' goal was simply to stop "these coward terrorists who are trying to destabilize our country."
Even as Allawi was urging on the troops, powerful Sunni and Shiite clerics were sending the opposite message. The Sunni Muslim Scholars Association and a representative of anti-American cleric Muqtada al-Sadr called on Iraqi soldiers not to fight alongside the Americans and against their countrymen.