An AP reporter saw the first of the turboprop-driven aircraft after it landed at the airfield this week. Four are expected.

The Iraq-based special forces command controlling the AC-130s, the Combined Joint Special Operations Task Force, said it would have no comment on the deployment. But the plan's general outline was confirmed by other Air Force officers, speaking anonymously because of the sensitivity of the subject.

Military officials warned that disclosing the location of the aircraft's new base would violate security provisions of rules governing media access to U.S. installations.

The four-engine gunships, whose home base is Hurlburt Field in Florida, have operated over Iraq before, flying from airfields elsewhere in the region. In November 2004, air-to-ground fire from AC-130s supported the U.S. attack that took the western city of Fallujah from insurgents. Basing the planes inside Iraq will cut hours off their transit time to reach suspected targets.

The left-side ports of the AC-130s, 98-foot-long planes that can slowly circle over a target for long periods, bristle with a potent arsenal — 40 mm cannon that can fire 120 rounds per minute, and big 105 mm cannon, normally a field artillery weapon. The plane's latest version, the AC-130U, known as "Spooky," also carries Gatling gun-type 20 mm cannon.

The gunships were designed primarily for battlefield use to place saturated fire on massed troops. In Vietnam, for example, they were deployed against North Vietnamese supply convoys along the Ho Chi Minh Trail, where the Air Force claimed to have destroyed 10,000 trucks over several years.

The use of AC-130s in places like Fallujah, urban settings where insurgents may be among crowded populations of noncombatants, has been criticized by human rights groups.

The slow-moving AC-130s also offer an intelligence gathering advantage in the Iraq fight: sophisticated long-range video, infrared and radar sensors.

American commanders are marshaling all available tools to detect the Iraqi insurgents' stealthy operations, especially at night, when they plant roadside bombs targeting American road patrols and convoys.

The Air Force's senior tactical commander in Iraq said the AC-130 can be both a high-intensity and low-intensity weapon.

"It's got tons of guns, and it's got all kinds of stuff on it that can be applied to the problems you have," Brig. Gen. Frank Gorenc, who refused to discuss the current AC-130 deployment, said in an AP interview.

That "stuff" includes "the ability to take these high-tech pods and to use them to find guys planting (bombs) and to find other nefarious activity," he said.

The Predator drone — the MQ-1 unmanned aerial vehicle — has been a reconnaissance workhorse in Iraq, but Air Force officers say they don't have enough to meet demand for missions. The fiscal 2007 Defense Department budget proposed last month by the Bush administration envisions spending $1.6 billion on additional reconnaissance drones.