A team of U.S. and Iraqi public health researchers has estimated that 600,000 civilians have died in the violence across Iraq since the 2003 U.S.-led invasion, the highest estimate ever for the war's death toll, The New York Times reported on Wednesday (Oct 11th).

The figure breaks down to about 15,000 violent deaths a month, a number that is quadruple the one for July given by Iraqi government hospitals and the morgue in Baghdad and published last month in a United Nations report in Iraq.

That month was the highest for Iraqi civilian deaths since the invasion.

But the number is an estimate and not a precise count, and researchers acknowledged a margin of error that ranged from 426,369 to 793,663 deaths, the report said.

It is the second study by researchers from the Johns Hopkins Bloomberg School of Public Health. It uses samples of casualties from Iraqi households to extrapolate an overall figure of 601,027 Iraqis dead as a result of violence between March 2003 and July 2006.

The findings of the previous study, published in 2004 in The Lancet, a British medical journal, had been criticized as high, in part because of its relatively narrow sampling of around 1,000 families, and because it carried a large margin of error, according to the report.

The new study is more representative, and the sampling is broader: it surveyed 1,849 Iraqi families in 47 neighborhoods across Iraq. The selection of geographical areas in 18 regions across Iraq was based on population size, not on the level of violence, the researchers said.

The U.S. military has released rough counts of average numbers of Iraqis killed and wounded in a quarterly accounting report mandated by Congress.

In the report, "Measuring Stability and Security in Iraq," daily averages of dead and wounded Iraqi civilians, soldiers and police officers rose from 26 a day in 2004 to almost 120 a day in August 2006.

The mortality rate before the U.S. invasion was about 5.5 people per 1,000 per year, the study found. That rate rose to 19.8deaths per 1,000 people in the year ending in June.

Gunshots were the largest cause of death, the study said, accounting for 56 percent of all violent deaths, while car bombs accounted for about 13 percent. Deaths caused by the U.S. military declined as an overall percentage from March 2003 to June 2006.

Editor: Donald