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The Kurdish commander stared down a road shimmering in the heat, then gestured to where the Islamic militants were deployed, plotting their next advance on this dusty Iraqi frontier town.

There was very little his Kurdish fighters could do about it.

"They have better weapons," Lt. Col. Saadi Soruchi said of the insurgents. "American weapons."

The Kurdish forces trying to defend frontline towns like Makhmour in their autonomous region of northern Iraq have felt the brunt of the Islamic extremist fighters' attacks and know how ferocious they are. The militants are bristling with American weapons and armored Humvees looted from Iraqi arsenals, giving them a powerful edge.

After Washington's promises to arm them, the Kurds say they badly need heavier weapons from the United States to stem the expansion of the Islamic State group.

The Kurdish fighters, also known as peshmerga, say they have yet to receive any new weaponry, even though U.S. officials said this week that they have been quietly arming the Kurds since June, when the Islamic State militants first swept into Iraq.

"I saw it on the breaking news," Soruchi said of the U.S. announcement, as he strode past Kurdish troops lounging in the shade at a sweltering, sand-whipped checkpoint. Surprised by their commander's visit, the men quickly snapped to attention.

Earlier this week, Lt. Gen. William Mayville told reporters at the Pentagon that the U.S. was planning to provide the Kurds with heavy weapons that are effective against the Islamic State's "technical vehicles" and longer-range guns. Weapons of that sort would include mortars and rocket-propelled grenades

The peshmerga say the lack of weaponry is becoming more urgent as the militants advance using armor the Kurds aren't equipped to fight.

In particular, the insurgents have seized American Humvees — vehicles that are so toughly armored that Kurdish fighters say they are struggling to penetrate them at anything but very close distance. The perilous task is made more dangerous because militants rig themselves, and the vehicles, with explosives.

Although the U.S. has been conducting airstrikes to defend some Kurdish positions, including Makhmour, the peshmerga say they want to protect their own frontiers from the Islamic State fighters.

The al-Qaida breakaway group has seized broad swathes of territory straddling the Iraqi-Syria border as it expands the Islamic state, or Caliphate, it has established there, imposing its harsh interpretation of Islamic law on the region's inhabitants. Last week, Islamic State fighters captured the country's largest hydroelectric dam and surrounding areas, including Makhmour, causing the exodus of tens of thousands of Iraqis, among them Christians and Yazidis, an ancient minority sect.

The emboldened militants also tried to seize the Kurdish city of Irbil, attacking a checkpoint 20 miles (35 kilometers) from the regional capital. They were pushed back by U.S. airstrikes.

The Islamic State acquired the American weapons from three batallions of Iraqi soldiers who fled in June as the militants advanced on western and northern sectors of the country in a lightning strike.

The militants began their Aug. 7 attack on Makhmour with mortars, the pounding explosions clearing the area of peshmerga fighters. They then rushed in with low-slung armored Humvees mounted with heavy machine guns.

Corp. Zorban Mirkhan said the peshmerga's only defense against the Humvees were rocket-propelled grenades that had to be fired from a distance no greater than 300 feet (100 meters).

"We are hiding and waiting for them, then we attack," said Zorban, pointing to dirt mounds, trenches and concrete blast walls littered with bullet casings and empty shells from the battle for the town.

Another peshmerga fighter said the work was made even deadlier because the militants' vehicles were rigged with explosives.

Eventually, the Kurdish forces fled to the nearby hills on a command to retreat, Mirkhan said, and the U.S. military airstrikes began shortly after. In the face of the onslaught, the militants retreated and Kurdish forces were able to retake the town.

Underscoring the flimsiness of peshmerga equipment, two soldiers showed the spray of bullet holes that burst through the civilian jeep they were driving during the Makhmour battle. When asked what protective gear they wore, they laughed and pointed at their own skin. Later, they proudly showed selfies taken with slain Islamic State militants.

The Kurdish fighters said that their battlefield experience and bravery would ultimately prevail in defending their borders. Kurds have fought for decades in their quest for independence, and see the fight against the Islamic State as the latest in a litany of obstacles to statehood.

"We have our weapons and we are brave," said Corp. Mirikhan as other peshmerga fighters nodded in agreement.

Lt. Col. Sorchi sighed.

"This is not a fight of people. It is a fight of weaponry," he said, ticking off the weapons the Kurds need: heavy machine guns, mounted machine guns, mortars, artillery, sniper weaponry, anti-tank weaponry, tanks — and more Humvees.

Although senior American officials said Monday that U.S. intelligence agencies are directly arming the Kurds, a major policy shift after years of just working with the central Baghdad government, U.S. officials have not said precisely what weapons they intend to supply to Kurdish forces.

Kurdish fighters do have some American equipment, they said, but it, like the weaponry in the militants' hands, was looted from deserting Iraqi soldiers in June. That includes two Humvees with mounted machine guns, and an APC parked at the Makhmour front.

On the frontline some 20 miles (35 kilometers) from the regional Kurdish capital, Irbil, peshmerga fighters showed off a Humvee containing a robotic device that could detect and dismantle the roadside bombs that militants have planted along patrolling routes of the frontier.

Suggesting a lack of faith in the peshmerga's ability to defend them, residents of Makhmour abandoned the town on Tuesday, padlocking their homes and leaving the trash uncollected.

Vehicles piled high with mattresses whizzed out of town, some with children perilously perched on top.

Idris Omar's family was stripping their home of all valuables and was heading to Irbil, where it was safer.

"We don't feel secure here," he said.