WASHINGTON ( CNN ) -- All major indicators of violence in Iraq have dropped by between 40 and 80 percent since February 2007 , when President Bush committed an additional 30,000 troops to the war there , the Pentagon reported Monday . The quarterly report to Congress noted that the military , political and economic gains made in the five-year-old war remain `` fragile , reversible and uneven , '' and that Islamic jihadists loyal to al Qaeda in Iraq remain capable of high-profile attacks . But civilian deaths have dropped from a peak of nearly 4,000 a month from December 2006 to January 2007 to about 500 a month as of May , and U.S. troop deaths have dropped from 126 in May 2007 to an all-time low of 19 in May 2008 . The report cited the emergence of the Sons of Iraq as a major reason for the downturn in civilian-oriented violence and deaths . The groups are made up of an estimated 90,000 Iraqis , often former insurgents , paid by U.S. commanders to help protect neighborhoods and provide intelligence on extremists . U.S. troop deaths and civilian deaths spiked in March , when Iraqis battled militia forces loyal to Shiite cleric Muqtada al-Sadr in Basra . At the end of March , an operation in Sadr City by U.S. and Iraqi forces to clear out insurgents firing rockets into the Green Zone also kept the death toll up , according to the report . But while the death toll went up in March , it remained lower than the numbers that prevailed before the `` surge '' campaign began in early 2007 . The next April and May saw a sharp downturn in deaths across the board , the report found . The fighting in Basra and Baghdad was a major test for Iraqi troops . Military officials said the Iraqi operation in Basra initially looked like a failure , but has turned out to be a success as Iraqi troops continue to hold and stabilize the southern city . In ongoing operations in the northern city of Mosul to drive out al Qaeda , Iraqi forces are showing clear signs of independent operational capability with little to no U.S. help , U.S. military officials said . The report suggested those successes are bolstering the ranks : More than 27,000 Iraqis have joined the country 's security forces since the last Pentagon report , in March , bringing the total number of Iraqi soldiers and police to about 560,000 . Since the March report , the Iraqi government focused on resolving conflicts from Basra and Sadr City that dominated the political and security landscape over the past three months , the report said . The report also said increasing oil export revenues are putting more money into the country for development , reconciliation programs and security . Insurgents continue to strike , however . An attack by a female suicide bomber Sunday in Baquba , which killed a reported 15 people , is one example of instability in regions with a heavy insurgent presence . While death tolls are down , the report highlighted the negative influence Iran is having inside Iraq . The report said Iraq 's neighbor `` continues to fund , train , arm and guide '' anti-American `` special groups , '' the U.S. term for splinter factions of al-Sadr 's Mehdi Army and other Shiite militants . Iran has denied U.S. allegations it is supporting insurgent factions within Iraq . But U.S. and Iraqi troops have discovered Iranian weapons inside Iraq , including Iranian made roadside bombs -- and during the fighting in Basra , large stashes of Iranian-made weapons were found with manufacture dates on them as recent as this year , according to U.S. military officials . The report said the Iraqi government continues to press the Iranians , who deny blame . May 2008 marked a sharp drop in high-profile attacks from al Qaeda , according to the report . Attacks in May hit a two-year low , about 70 percent lower than the peak in March 2007 . The U.S. military said the drop is connected to U.S. and Iraqi operations directed at al Qaeda , but pointed out that in a single day -- April 15 -- a high-profile attack killed more than 150 people .
Pentagon 's quarterly report to Congress notes violence reduction . It also notes that jihadists loyal to al Qaeda in Iraq are still a threat . Report credits Sons of Iraq , former insurgents who are now being paid by U.S. Increasing oil export revenues are putting more money into Iraq , report says .