It was the first time in the war that American soldiers have joined with local fighters to battle Iraqi forces.

A Kurdish political chief, Wajih Barzani, hailed the joint action as the formal opening of the long-delayed northern front of the war. He also praised the "perfect cooperation" between Kurdish and U.S. forces.

The American soldiers who led Thursday's raid clearly were impressed with the local guerrillas, who are known as peshmerga, or "those who face death."

"We have every radio and every gadget there is, but the pesh can do it all without any of this stuff," Staff Sgt. Terry Singer of Choctaw, Okla., said as he took a breather in an abandoned Iraqi bunker. "They're extremely disciplined. They're great."

"They don't have much in the way of uniforms, and they might not know about detailed military tactics and all that, but they do know how to fight," said another Special Forces sergeant.

The two leading Kurdish factions employ an estimated 70,000 well-organized but lightly armed guerrillas in the Kurdish autonomous region of northern Iraq. Kurdish leaders have placed those forces under American command and have pledged not to move against Mosul and the oil-rich city of Kirkuk without U.S. permission.

Thursday's raid began at midmorning, as a wave of peshmerga moved on Iraqi bunkers tucked into the hills above the village of Kalak.

"Two U.S. soldiers led us, and they were the first ones over the hill," said Salah Saleh, a 22-year-old from Kalak who was right behind the Americans. "We didn't have to fire a single shot. The Iraqis had already fled."

The Iraqis had laid a few anti-vehicle mines before they retreated, but those were quickly discovered and defused. Guerrillas also found large supplies of gas masks, but there was no evidence of chemical weapons.

The Iraqis withdrew to Mankubah, about 8 miles to the west, then spent most of the afternoon fighting the Americans and the guerrillas to a standstill at the Khazir Bridge there. The town of 1,500 is a dozen miles east of Mosul.

Guided by the Special Forces troopers on the ground, Air Force jets hammered the Iraqis with bombs and laser-guided missiles. Iraqi troops used sniper fire, mortars and light artillery to halt the guerrillas' advance.

Throughout the afternoon, knots of peshmerga hunkered down in a field of knee-high wheat, poking up their heads occasionally to fire machine-gun bursts at Iraqi snipers. Around midday, with bullets whizzing over their heads and Iraqi mortars popping to their left and right, one group of guerrillas managed to wolf down a quick lunch: tomatoes, cool water and wedges of fresh bread dipped into a plastic bucket of sheep-milk yogurt.

At one point, the Iraqis had the Kurds and U.S. soldiers beating a retreat. As an American sergeant made it back to a safe bunker, he clapped a peshmerga on the back, smiled and said, "It was nice being pinned down with you."