BAGHDAD , Iraq ( CNN ) -- The U.S. military says a recent raid uncovered a detailed letter from an al Qaeda in Iraq militant to the group 's leader about how the insurgent network should continue to generate economic chaos and `` psychological conflict '' and must bear down against American-backed Sunni militias . An Iraqi mother and daughter are helped Tuesday after a car bombing in Baquba blamed on al Qaeda in Iraq . Maj. Gen. Kevin Bergner told reporters at a news conference on Wednesday about a letter to Abu Ayyub al-Masri , the head of al Qaeda in Iraq , from a militant named Abu Safyan . The document was posted on the Multi-National Forces-Iraq Web site . The sentiments reflect the tenacity of and continuing challenges posed by the predominantly Sunni militant network believed to be responsible for bombings that erupted across Iraq on Tuesday . Bergner said it `` provides further evidence about the strategy and tactics of violence '' the group is pursuing . Bergner said a March 5 raid northwest of Baghdad resulted in three insurgents killed , including Abu Safyan , and three others captured . Troops seized a suicide vest , computer material and a stack of documents , including the document from Abu Safyan -- who was believed to be from Diyala province . Abu Safyan lays out a variety of tactics that militants should pursue . `` We must always leave the enemy in psychological conflict '' so that `` they can never have stability , '' according to the document . With such instability , they `` will not all unite against us , '' it adds . Bergner said that while authorities are investigating Tuesday 's bombings in Baghdad , Ramadi , Mosul , and Baquba that killed 60 people and wounded more than 100 others , the strikes have the `` hallmark '' of being perpetuated by al Qaeda in Iraq . The group has been considered the coalition 's top foe in Iraq , even though troops have been distracted in recent weeks by fighting rogue Shiite militias . Al Qaeda in Iraq has been described by military officials as having a largely foreign leadership but made up of Iraqis . It is distinct from al Qaeda in Afghanistan and Pakistan , but it is not clear how closely both the Iraqi and the South Asian al Qaeda groups cooperate . The letter details the need for fostering `` security chaos '' among the anti-al Qaeda in Iraq and mostly Sunni awakening groups , Shiites and Kurds , the coalition forces , and the government . `` This will lead to weaken them , particularly the Maliki Shia government , by wisely , intelligently and cautiously spreading sedition among them , '' the letter said , referring to Prime Minister Nuri al-Maliki . In the letter , Abu Safyan considers awakening groups a top threat to al Qaeda in Iraq and proposes a media campaign that would discredit the awakening forces by passing along false information about them . The jihadi says al Qaeda in Iraq militants should consider infiltrating the government and security forces to foster trust . That atmosphere would enable militants to conduct attacks , including strikes against Shiites . `` We will work against them and attack them as they fight among themselves , '' Abu Safyan is quoted as saying . Abu Safyan also calls for the disrupting the economy by attacking gas and oil fields , pipelines , tankers , electric stations and power lines . He suggests contaminating water lines and lakes . Such sabotage would serve to `` halt payment of the military and police salaries and the awakening movement associated with the occupier and Maliki 's malignant government . Even the American Army will weaken since it depends on the Iraqi oil and gas wealth . The enemy will gradually drown step by step . '' Abu Safyan talks about the need to `` bring many brothers who have sharia knowledge and abide by the teachings of Islam from the outside of Iraq . '' `` They will explain to the people why we are fighting and whom we are fighting with , we must explain to them whom the mujahideen are and who are the people we 're fighting . '' The militant also called for good protection of communities under their control . `` We must dig trenches around the villages and cities to prevent the enemy from entering our areas , '' the document said . Abu Safyan also called for organizing fighting groups by having an emir as commander with sniper , assassination and martyrs ' groups . It also cautions vigilance against allowing the `` enemy '' to infiltrate its apparatus and exhorts its fighters to keep silent about operations . Sometimes , `` they speak of our operations and area 's secrets among their families and their wives in their houses , which unfortunately lead to the spread of our secrets . '' E-mail to a friend .
Letter from al Qaeda in Iraq militant found after he was slain , U.S. says . Letter urges al Qaeda in Iraq to fight against American-backed Sunni militias . Document also cautions vigilance against infiltrators .