Air strikes and artillery barrages have taken a heavy toll among the most vulnerable of the Iraqi people, with children and women forming a disproportionate number of the dead.
Analysis carried out for the research group Iraq Body Count (IBC) found that 39 per cent of those killed in air raids by the US-led coalition were children and 46 per cent were women. Fatalities caused by mortars, used by American and Iraqi government forces as well as insurgents, were 42 per cent children and 44 per cent women.
Twelve per cent of those killed by suicide bombings, mainly the tool of militant Sunni groups, were children and 16 per cent were females. One in five (21 per cent) of those killed by car bombs, used by both Shia and Sunni fighters, was a child; one in four (28 per cent) was a woman.
The figures, compiled by academics at King's College and Royal Holloway, University of London, show that hi-tech weaponry has caused lethal damage to those in the population who would be furthest away from the conflict.
The victims of one of the most brutal and common types of killings in the war - abduction and execution by death squad - were 95 per cent men, many of them bearing marks of torture.
The report, The Weapons That Kill Civilians, Deaths of Children and Noncombatants in Iraq, was compiled from a sample of 60,481 deaths in 14,196 events over a five-year period since the 2003 invasion. Civilian casualties from concentrated bouts of violence, such as the two sieges of Fallujah, were excluded.
IBC estimates that the total deaths in the conflict so far number 99,774. The medical journal The Lancet has maintained in another study that more than 600,000 people were killed in the first three years of the war. IBC holds that the indiscriminate nature of the fatalities caused by air strikes shows they should not be used in urban areas.
Growing anger over civilian casualties caused by air raids in another front of the "war on terror", Afghanistan, has led to the US, UK and their Nato partners reviewing their policy of using warplanes. Hamid Karzai, the Afghan President, recently said this had become the most contentious issue between him and Western powers.
From 2004 to 2007, the overall tonnage of munition dropped from planes in the Afghan conflict rose from 163 tonnes a year to 1,956 tonnes, an increase of 1,100 per cent. Since 2001 the US air force has dropped 14,049 tonnes of bombs in Afghanistan and 18,858 in Iraq.
Professor John Sloboda, of Royal Holloway, co-author of the report, said: "Our weapon-specific findings have implications for a wide range of conflicts, because the patterns found in this study are likely to be replicated for these weapons whenever they are used.
*Last night a US army sergeant was facing life imprisonment after being found guilty of executing four Iraqi detainees in 2007. Master Sgt John Hartley shot four men in the head and dumped their bodies in a canal in West Rasheed area of Baghdad. He is due to be sentenced today.