FALLUJAH, Iraq – The battle to retake Fallujah began Tuesday where Marines least expected it: near a cluster of rye fields where the locals seemed friendly and children passed the day playing soccer.

“It looks like Nebraska – with palm trees,” said Lance Cpl. Justin Howe, 25.

Two days after cordoning off this restive city 30 miles west of Baghdad, Marines were beginning to view the quiet, residential neighborhood as relatively safe. Local farmers appeared receptive to their calls for cooperation, and Marines had offered to pay compensation to a few whose property was damaged by their operations.

So when a squad of Marines emerged from behind their covered checkpoint Tuesday to begin a foot patrol, enemy fire was not what they expected.

Within seconds, everyone was diving for cover amid a barrage of bullets.

“There was fire all around my feet,” said one of the Marines in the patrol.

One American was hit by a bullet that pierced his helmet and lodged in his head. He was expected to survive. Another Marine was shot in the leg.

Tanks, Humvees and helicopters quickly arrived to attack parts of the neighborhood, destroying one building. After treating the Marine’s head injury, one soldier grabbed his M-16 and joined the retaliatory strike.

Insurgents, meanwhile, were demonstrating a resolve of their own.

When Marines entered the neighborhood in tanks and helicopters, they held their positions and fired back with rifles, mortars and small arms.

Residents reported that insurgent cells, which had been lying low in recent days, had a higher profile Tuesday, openly carrying weapons and positioning grenade launchers in the streets. One carload of Iraqis was captured while attempting to plant homemade bombs in the road in broad daylight.

“We will continue to resist them,” said Abu Khamis Khulaifawi, who described himself as part of the insurgency in Fallujah. “We have enough mortars, enough rocket-propelled grenades and enough light arms.”

Insurgents also appeared to have a strategy to defend the city.

They have blocked streets in an attempt to divert military vehicles and have used an antiaircraft gun to try to shoot down helicopters. They are using buses to transport fighters and have darted in with cars to retrieve their dead after battles.

Fallujans set up a field hospital to stand in for the city’s main facility, which is close to Marine positions.

Some residents praised the insurgents for their tenacity.

“It seems that they have succeeded in preventing the Americans from entering the city,” said Ali Naif, a student at Al Anbar University.

But Maj. Brandon McGowan, executive officer of the 2nd Battalion, 1st Regiment, said the Marines’ mission was going smoothly, and he was not surprised by the insurgents’ willingness to attack. In fact, he said, he was counting on it.

“If they want to come out and fight, that’s fine with us,” he said. “That way, we don’t have to go house-to-house to find them. They’ll fall into our hands more easily.”