Now Zad, Afghanistan ? Missiles, machine guns and strafing runs from fighter jets destroyed much of a Taliban compound, but the insurgents had a final surprise for a pair of U.S. Marines who pushed into the smoldering building just before nightfall.

As the two men walked up an alley, the Taliban opened fire from less than 15 yards, sending bullets and tracer fire crackling inches past them. They fled under covering fire from their comrades, who hurled grenades at the enemy position before sprinting to their armored vehicles.

The assault capped a day of fighting Saturday in the poppy fields, orchards and walled compounds of southern Afghanistan between newly arrived U.S. Marines and well dug-in Taliban fighters. It was a foretaste of what will likely be a bloody summer as Washington tries to turn around a bogged-down, eight-year-old war with a surge of 21,000 troops.

“This was the first time we pushed this far. I guess they don’t like us coming into their back door,” said Staff Sgt. Luke Medlin, who was sweeping the alley for booby traps as Marine Gunner John Daly covered him from behind when the Taliban struck.

“And now they know we will be back,” said Medlin, from Indiana.

The fighting was on the outskirts of Now Zad, a town that in many ways symbolizes what went wrong in Afghanistan and the enormous challenges facing the United States. It is in Helmand province, a center of the insurgency and the opium poppy trade that helps fund it.

Like much of Afghanistan, Now Zad and the surrounding area were largely peaceful after the 2001 invasion. The United Nations and other Western-funded agencies sent staff to build wells and health clinics.

But in 2006 — with American attention focused on Iraq — the insurgency stepped up in the south. Almost all the city’s 35,000 people fled, along with the aid workers.

British and Estonian troops, then garrisoned in Now Zad, were unable to defeat the insurgents. They were replaced last year by a small company of about 300 U.S. Marines, who live in a base in the center of the deserted town and on two hills overlooking it.

The Taliban hold much of the northern outskirts and the orchards beyond, where they have entrenched defensive positions, tunnels and bunkers.

The Marines outnumber the Taliban in the area by at least 3-to-1 and have vastly superior weapons but avoid offensive operations because they lack the manpower to hold territory once they take it. There are no Afghan police or troops here to help.

“We don’t have the people to backfill us. Why clear something that we cannot hold?” said Lt. Col. Patrick Cashman, head of the battalion in charge of Now Zad and other districts in Helmand and Farah provinces, where some 10,000 Marines are slowly spreading out in the first wave of the troop surge.

Cashman said the Marines did not intend to allow the Taliban free rein in parts of Now Zad, but was unable to give any specific plans or time frame for addressing what he acknowledged is “a bad situation.”

Saturday’s mission was aimed at gathering intelligence and drawing a response from enemy positions close to a street called “Pakistani alley” because of one-time reports suggesting fighters from across the border had dug in there.