US: A team of American and Iraqi epidemiologists estimates that 655,000 more people have died in Iraq since coalition forces arrived in March 2003 than would have died if the invasion had not occurred.
The estimate, produced by interviewing residents during a random sampling of households throughout the country, is far higher than ones produced by other groups, including Iraq's government.
It is more than 20 times the estimate of 30,000 civilian deaths that President Bush gave in a speech in December. It is more than 13 times the estimate of roughly 50,000 civilian deaths made by the British-based Iraq Body Count research group.
The surveyors said they found a steady increase in mortality since the invasion, with a steeper rise in the last year that appears to reflect a worsening of violence.
Of the total 655,000 estimated "excess deaths", 601,000 resulted from violence and the rest from disease and other causes, according to the study.
This represents about 500 unexpected violent deaths per day throughout the country.
The survey was done by Iraqi doctors and overseen by epidemiologists at Johns Hopkins University's Bloomberg School of Public Health. The findings were being published online yesterday by British medical journal the Lancet.
The same group in 2004 published an estimate of roughly 100,000 deaths in the first 18 months after the invasion. That figure was much higher than expected, and was controversial. The new study estimates that about 500,000 more Iraqis, both civilian and military, have died since then - a finding likely to be equally controversial.
Both this and the earlier study are the only ones to estimate mortality in Iraq using scientific methods. The technique, called "cluster sampling", is used to estimate mortality in famines and after natural disasters.
A US defence department spokesman did not comment directly on the estimate.
Ronald Waldman, an epidemiologist at Columbia University who worked at the Centres for Disease Control and Prevention for many years, called the survey method "tried and true", and added that "this is the best estimate of mortality we have".
This view was echoed by Sarah Leah Whitson, an official of Human Rights Watch in New York, who said, "We have no reason to question the findings or the accuracy" of the survey.
The survey was conducted between May 20th and July 10th by eight Iraqi doctors organised through Mustansiriya University in Baghdad.
They visited 1,849 randomly selected households that had an average of seven members each.