By MARK MAZZETTI Published: October 18, 2008

WASHINGTON – They wake before dawn, with time to exercise, eat and pray before the day’s first class in firing Kalashnikov rifles.

Over the next eight hours, they practice using bazookas or laying roadside bombs, with a break for lunch and mandatory religious instruction.

There is free time in the evening to watch television or play Ping-Pong.

Lights out at 11 p.m.

Such is a typical day at a dusty military base outside Tehran, where for the past several years members of the Iranian Revolutionary Guard Quds Force and Lebanese Hezbollah operatives have trained Iraqi Shiites to launch attacks against American forces in Iraq, according to accounts given to American interrogators by captured Iraqi fighters.

American officials have long cited Iranian training and weapons as reasons for the lethality of attacks by Shiite fighters in Iraq. Iranian officials deny that such training takes place.

Now, more than 80 pages of newly declassified intelligence documents for the first time describe in detail an elaborate network used by Iraqis to gain entry into Iran and train under Iranian supervision. They offer the most comprehensive account to date to support American claims about Iranian efforts to build a proxy force in Iraq. Those claims have become highly politicized, with Bush administration critics charging that accounts of Iranian involvement have been exaggerated.

The prisoners’ accounts cannot be independently verified. Yet the detainees gave strikingly similar details about training compounds in Iran, a clandestine network of safe houses in Iran and Iraq they used to reach the camps and intra-Shiite tensions at the camps between the Arab Iraqis and their Persian Iranian trainers.

Although attacks on Americans by Shiite militias have greatly decreased this year, military and intelligence officials said there was evidence that the militias, sometimes referred to as “special groups,” were now returning to Iraq to disrupt coming elections and intimidate residents. Maj. Gen. Jeffery W. Hammond, the commander of American forces in Baghdad, said recently that he believed that some militia fighters had returned to the capital in recent weeks.

The documents, compiled by the Combating Terrorism Center at West Point, are a collection of interrogation reports based on accounts of more than two dozen Shiite fighters captured in Iraq in 2007 and 2008. (The documents are available online at ctc.usma.edu/Iran_Iraq.asp.) The center is a research organization that compiles and analyzes intelligence documents related to Al Qaeda, Iraq, Iran and other topics.

The documents portray an Iranian strategy to use Iraqi Shiites as surrogates, in part to avoid the risk of Iranians being captured in Iraq. In one of the intelligence reports, a prisoner tells his captors that “Iran does not want to fight a direct war” with American forces in Iraq because Tehran worries that the United States would destroy Iran.

American intelligence officials say they believe that since a handful of Iranian Revolutionary Guard operatives were captured in Baghdad in 2006, Iran shifted its strategy to bringing small groups of Iraqis into Iran. The Iraqis are then sent back to their country to train larger cadres of Shiite militants.

One senior American intelligence official said there were indications that the training programs in Iran might have significantly expanded this year to accommodate the scores of Iraqi militia fighters who fled Iraq during the Iraqi military’s campaigns in Basra and Baghdad.

Brian Fishman, director of research at the Combating Terrorism Center and a co-author of a new study about Iran’s political and military influence in Iraq, said that even though Iran was not in direct command of militia groups in Iraq, the training was one of the means at Iran’s disposal to increase or decrease its influence in Iraq at will.

“Having the militia allies is a hedge,” he said. “If things turn against Iran politically, it gives them a lever to pull.”

American officials say it is still murky just how much of a direct role senior Iranian officials take in the training, although they say they believe that it takes place with at least the tacit approval of elements of Iran’s government. The documents do not provide any direct evidence of senior Iranian government officials overseeing the training.

The new Iran study, written by Mr. Fishman and Col. Joseph H. Felter, concludes that Iran aims to attack American troops in Iraq in part to show off its own abilities and in part to “demonstrate a credible deterrent against a U.S. strike on Iran’s nuclear facilities.”

The captives gave detailed descriptions of daily routines in the Iranian camps, from the intensity of weapons training to the more mundane complaints of military life. One of the captured Iraqis described a mini-revolt among the trainees because they had not been issued socks to wear with their military boots.

The documents also reveal deep ethnic fissures between Iranian and Iraqi Shiites. The Iraqis complained that their Iranian trainers did not show them the proper respect and that they made disparaging remarks about Moktada al-Sadr, the Iraqi Shiite cleric who has led an anti-American resistance movement in Iraq

“Iraqi Shia are superior to Iranians because Iraqi Shia are moral, good, compassionate and emotionally sensitive,” one detainee said. “Iranians are not moral, are not sensitive and believe they are superior to everyone.”

By contrast, the Iraqis said they tended to forge closer bonds to the Lebanese Hezbollah fighters, Arabs who share a common language with the Iraqis.

After they had been selected for training in Iran, some of the trainees told their families they were going to the Iraqi city of Najaf to help guard the holy Shiite shrines there. Actually, the trainees usually made their way to Amara, a town in eastern Iraq not far from the Iranian border. There, they met their contact person at a local garage, where they were given small sums of money and stowed in safe houses around the city.

After a day or two, those with passports were driven by bus or taxi over the Iranian border to cities in western Iran like Ahvaz or Kermanshah. One detainee reported that the Iranian training was usually scheduled around major Shiite holidays, when large numbers of pilgrims cross the border and there is a better chance that the movement of the fighters will go unnoticed.

Those without passports were usually driven at night to marshlands, where they boarded rowboats to be ferried over the border and picked up by a waiting vehicle.

After spending a night in Ahvaz or Kermanshah, the trainees were brought to a local airport and flown to Tehran, where they were picked up and driven to a military base hours outside the city. Several of the detainees identified the camp as the Sayid al-Shahada military base.

Once at the base, trainees were issued a “tracksuit, tennis shoes, towel, and military food,” one of the prisoners reported.

“The refrigerator was filled with a lot of food and fruit,” he said.

They spent the next month training to fire small-caliber firearms, mortars and antiaircraft weapons, and learning how to carry out ambushes. They took classes in camouflage and daily religious instruction.

Some trainees participated in a special “engineer course” that trained militants how to lay roadside bombs. But only “smart” trainees were allowed to take part in the engineer training, according to one captive who said he was deemed not intelligent enough for this specialized training.

“If you are not smart, no one will waste the time and expenses to send you to Iran to train to be an engineer because you will fail,” says one of the interrogation reports. “Detainee did not care about engineer training and did not want to come back to Iran because their training was a waste of time and detainee had to leave his family for nothing.”

Other prisoners shared this dim view of the training, telling American interrogators that a separate training course run by Hezbollah operatives in Lebanon was far superior to the training in Iran.

To get to the training course in Lebanon, the detainees report, the Iraqis were taken by bus to an airport in Iran, where they then flew to Damascus, Syria, and were picked up and driven to the Lebanese border. Once in Lebanon, they said, they participated in several more weeks of training, led byHezbollah operatives, in “weapons inventory control,” “project planning” and communications.

Those Iraqi trainees who did not go on to Lebanon had time for sightseeing during their remaining days in Iran, they reported. Some went to Tehran to visit religious shrines around the capital city. Others traveled to the Iranian city of Mashhad to shop, visit the tourist gardens or go to the zoo.