The Kurds' yellow flag was wedged into the rusty bridge at Khazer, a key crossing point on the road to the northern Iraqi city of Mosul. Militiamen allied with U.S. forces marched over single file, their rucksacks and guns swaying on their backs.

The two-day battle for the bridge that ended Friday put an unusual partnership on display: computer-coordinated U.S. air power and the rugged simplicity of the Kurdish guerrillas known as peshmerga, or "those who face death."

"The Iraqis are running," an Iraqi Kurd shouted as he crossed the bridge. "And we are chasing."

They passed the burning wreckage of an Iraqi military truck hit by coalition airstrikes. Two bodies lay on one side, their seared skin reflecting the sun like high-gloss plastic.

The Iraqis still clung to a position about a half mile west of the bridge and unleashed a heavy artillery barrage around Khazer early in the evening. The battle still raged at dusk, with U.S. B-52s bombing Iraqi positions.

Air attacks during the past week have forced Iraqi troops back from the border with the Western-protected Kurdish zone. In most places, Kurds simply moved into the abandoned territory to advance closer to the key prizes of Mosul and the oil center around Kirkuk.

At the far southern part of the Kurdish autonomous zone, Kurdish fighters are massing in preparation to move on a key target, the oil city of Khaneqin, 85 miles northeast of Baghdad. Some 1,800 fighters have gathered on the nearby front, up from 400 only weeks ago, and more than a 1,000 more are expected to join them in the next few days, said Mola Bakhtiyar, a high-level Kurdish political and military leader.

The thrust toward Khazer -- 18 miles east of Mosul and about 250 miles northeast of Baghdad -- reflected a new, aggressive Kurdish strategy. With U.S.-led soldiers on Baghdad's doorstep in the south, it could indicate the start of a bolder push to the capital from the north.

At noon, the 17th Battalion of the Kurdistan Democratic Party -- one of the two main Kurdish factions -- was within sight of Khazer from a hilltop dotted with foxholes once held by the Iraqis. Lt. Col. Tasim Hajiabdullah sent scouts from his battalion of about 1,700 through a pasture filled with yellow wildflowers to scan the Iraqi fortifications.

The report came back: sandbag bunkers and Iraqi soldiers with AK-47s. Mortars were seen. No big artillery or tanks.

"Good. Very good," said Hajiabdullah, who wore a red beret and khaki uniform with sharp creases and an old Iraqi army belt. "We will move slowly."

This was never part of the Kurdish fighters' doctrine. Through decades of conflict with Baghdad, the peshmerga was known for its fearless but uncoordinated tactics, each group acting as a free-lance strike force. But the Pentagon has demanded strict obedience to its war planning against Saddam Hussein.

The result has been unexpected restraint by the Kurds.

"The Americans decide every battle and how far we can go," said Shoukrin Nerwey, a top coordinator for Kurdish fighters.

The Kurds say they are fighting for a future semiautonomous state within an Iraqi federation, something they say they have been assured will include Kirkuk and Mosul.

U.S. soldiers moved through the Kurdish formations on Friday, apparently checking positions and directing airstrikes against the Iraqis. A B-52 bomber moved overhead in a lazy curve about 1:15 p.m. Moments later, a series of blasts hit Iraqi lines.

"They are pulling out," said Hajiabdullah. "We're moving."

Kurdish irregulars streamed forward. They moved rapidly, but under no apparent direct command. Some walked through fields; others took the road. Their packs bulged with extra clothes and colorful carpets used as bed rolls. A few carried grenade launchers on their shoulders. All had AK-47 rifles, some well-oiled and shiny, others showing their age.

Two Kurdish fighters prepared an anti-aircraft gun on the back of a truck bearing the lion's head emblem of their unit. They planned to use it against Iraqi troops if they staged a counter attack.

Then came more explosions near the bridge from another airstrike. Two American soldiers, wearing traditional red-checkered Kurdish scarves, drove through the field toward the town of Kalak, about six miles east.

Hidam Shamsadeen, a young Kurdish fighter, came running up the road carrying an 82 mm mortar launcher and tripod.

"I got this from the Iraqis," he yelled excitedly. "They left it behind. We'll use it against them now."

A teenager, holding the bright yellow banner of the Kurdistan Democratic Party, passed among fighters resting in the shade of a small cliff. He ran up to the only officer present.

"How far can we can go and put the flag?" he asked.

"Up to there," said the officer, pointing to a small hill less than a half mile from the bridge over the muddy and sluggish Mangouba River. "Don't go any farther. The Iraqis are firing back."

The retreating Iraqis opened up with automatic rifle fire that pinged off the bridge, forcing Kurds to run down the river bank for cover.

"Incoming!" a Kurdish fighter shouted. Those around him dove into Iraqi bunkers that had been abandoned shortly before. The whistle of Iraqi artillery passed over and the shell fell harmlessly on the ridge where the Kurdish offensive had begun earlier.

Moments later coalition warplanes blasted hills outside Khazer where the Iraqis had regrouped. The smoke was already rising by the time the thud reached the bridge.

"It's far away. The Iraqis are leaving," said Kamal Aziz, huddled with a dozen other fighters in a hillside dugout used to shelter Iraqi vehicles. "The bridge is ours."