Charging into previously unsecured areas, the Marines tried to provoke attacks in order to find Iraqi fighters and defeat them. A chaplain traveling with them handed out humanitarian packages to distrustful Iraqi civilians encountered along the way. 

In Nasiriyah, 130 miles south of Najaf and the scene of fierce fighting over the past week, a Marine raid secured buildings held by the Iraqi 11th Infantry Division that contained large caches of chemical decontamination equipment, weapons and ammunition. 

The U.S. Central Command reported that in one building Marines found more than 300 chemical suits and gas masks, atropine injectors, two chemical decontamination vehicles and other decontamination devices. 

In another, they found more than 800 rocket-propelled grenades, along with mines, hundreds of mortar and artillery rounds, and thousands of rifle rounds - so much, said Col. Ron Johnson, Task Force Tarawa Operations Officer, that "it would be too dangerous to the city to blow it in place. We are going to have to transport it somewhere safe." 

Army supply trucks appeared on the Marine route north for the first time Sunday, supporting field reports that U.S. Army and Marine forces were meeting for the first time in the ground invasion, which had the Marines trekking north along Route 80 - known as the "Highway of Death" - and Army forces punching their way across desert terrain. 

There were other pockets of Iraqi resistance in Sanawah, Karbala and Diwaniyah in south-central Iraq. Aircraft flying in these areas continue to take fire from machine guns, rocket-propelled grenades and anti-aircraft artillery. 

Using loud speakers mounted on their Humvees, U.S. soldiers securing Najaf's perimeter will soon begin beseeching its townspeople turn over paramilitary members. They also will stress that the Americans have no intention of harming civilians. 

Hill would not give a timeline for possibly entering the city. He said the 101st was hoping that Najaf residents would first rid the town of any paramilitary fighters. He said going in could make for slow fighting because "you have to own a building before you moved into another one." 

Najaf, one of the major religious sites of Islam, is the location of the tomb of Imam Ali, son-in-law of the prophet Muhammad, whose assassination led to the creation of the Shiite branch of the faith. 

"I think all of us here at Centcom recognize the historical and religious significance of An Najaf," said Lt. Mark Kitchens, a spokesman for U.S. Central Command in Qatar. "It's important to note coalition forces do not target cultural and religious sites and take the utmost care to avoid civilian casualties and collateral damage." 

Najaf is also known as the place where Ayatollah Ruhollah Khomeini, leader of Iran's revolution, lived in exile fomenting the fundamentalist Shiite revolution that overturned the Shah of Iran in 1979. 

Pushing through small arms and mortar fire, the division's 1st and 2nd brigades began surrounding the city on Saturday, setting up roadblocks. 

There were no reports of American casualties. 

"They are slowly, but surely, squeezing into the town," said Col. Michael Linnington, commander of the 3rd Brigade, which guards a forward operating base outside town that serves as a refueling area for the division's helicopters. 

A light infantry division, the 101st has a fleet of about 280 helicopters that allows it to be inserted and resupplied deep into enemy territory. 

The 101st moved by ground convoy and helicopter into central Iraq in recent days. But it has largely avoided ground combat because it moved behind the 3rd Infantry Division. 

In the wake of Saturday's suicide attack, Linnington said the division's soldiers were "very, very aggressive and very vigilant" about setting up roadblocks around Najaf. 

Iraq's vice president, Taha Yassin Ramadan, indicated that Saturday's attack was part of a coordinated effort to thwart invaders who can't be defeated by conventional warfare. 

"We will use any means to kill our enemy in our land and we will follow the enemy into its land," Ramadan said. "This is just the beginning." 

Coalition forces have since been ordered to shoot any suspicious vehicles that do not abide by warnings to stop.