FORT HUACHUCA, Ariz. — In the increasingly crowded classrooms on this weathered Army post, soldiers who used to be medics, mechanics and even Marines are taking crash courses in how to interrogate prisoners.

A nearby field recently cleared of desert brush and rattlesnakes is now lined with dozens of metal shipping containers converted to practice interrogation booths. Banks of DVD burners record every session so instructors can scrutinize their students' false starts, and fail them if they violate the Geneva Convention.

And in the looming Huachuca Mountains, Army engineers are building a facility for field exercises — a makeshift Muslim village where loudspeakers emit a muezzin's call to prayer and soldiers interrogate "insurgents" amid mock mortar attacks and suicide bombings.

Here in the southeastern corner of Arizona, the Army is looking for solutions to two of its biggest problems: the need for better intelligence on the insurgency in Iraq, and the cascade of prisoner abuse scandals triggered by Abu Ghraib.

As home to the U.S. Army Intelligence Center and School, Fort Huachuca is the principal training ground for interrogators, analysts and other military intelligence troops.

Some soldiers in these specialties have been a significant source of embarrassment to the Army in the past year, implicated in one detainee abuse case after another. But because intelligence is increasingly driving military operations in Iraq and elsewhere, troops with these skills are in acute demand. The Army is planning to add 9,000 "M.I." soldiers to its active-duty ranks over the next five years, including 3,100 interrogators.

As it trains the new specialists, Fort Huachuca is overhauling its approach. It wants interrogators better equipped to gather intelligence in an intense urban conflict, more familiar with the cultural nuances of the Muslim world, and better prepared to intervene when things go wrong.

Half of Fort Huachuca's soldiers will be deployed to Iraq or Afghanistan within 45 days of finishing instruction.

Phillip Seibel, 23, a reservist from Lodi, Calif., has been a telephone technician in the Army since shortly after joining the reserves six years ago. When he got a call from a sergeant in his unit earlier this year informing him that he was being reassigned to a military intelligence battalion, he barely blinked.

"I thought I was going to be running phone support for an M.I. unit," he said.

Instead, he was sent to Fort Huachuca, where he has spent the past 14 weeks studying interrogation methods.

Others in his class come from an array of military backgrounds: infantry, air defense, even an ex-Marine. "There are medics, MPs, mechanics," Seibel said. "You basically have a little of everything."

Training of previous generations of interrogators anticipated that they would spend most of their time questioning prisoners in detention camps far from the front lines. But in Iraq, they're being assigned to tactical teams that move through neighborhoods combing for intelligence on insurgents.

Largely because of the changing complexion of the job, the Army has renamed it, replacing interrogators with "human intelligence collectors." The Army has also eliminated language training for interrogator trainees. Instead, the Army is relying increasingly on contract interpreters; training at the institute is reserved for soldiers who re-enlist.