NEWS_ARTICLE.RttP{About 151,00 Iraqis killed since the U.S. led invasion}

About 151,000 Iraqi civilians were killed in the three years following the U.S.-led invasion of their country, according to World Health Organization (WHO) research published on Wednesday.

The new study, which said violent deaths could have ranged from 104,000 to 223,000 between March 2003 and June 2006, is the most comprehensive since the war started.

The study drew on an Iraqi health ministry survey of nearly 10,000 households -- five times the number of those interviewed in a disputed 2006 John Hopkins University study that said more than 600,000 Iraqis had died over the period.

While well below that figure, the United Nations agency's estimate exceeds the widely-cited 80,000 to 87,000 death toll by the human rights group Iraq Body Count, which uses media reports and hospital and morgue records to calculate its tally.

"There are a lot of uncertainties in making such estimates," WHO statistician Mohamed Ali, who co-authored the study, told reporters on a conference call.

He said insecurity made parts of Baghdad and Anbar provinces unreachable for those conducting the survey, which included questions about other topics including pregnancy and disease.

Many families also fled their homes as a result of the violence, and some left the country, making it hard to give a precise assessment of the violence in Iraq. As a result, Ali said the margin of error for the toll was relatively high.

Still, he said the household survey's large scale gave the findings more weight than previous attempts to estimate the number of Iraqis killed in battles between and among military forces, insurgents and sectarian fighters.

The John Hopkins University report, published by the British medical journal Lancet, which was based on a smaller-scale Iraqi survey, drew criticism from the White House and elsewhere for appearing to exaggerate the Iraqi death rate.

Iraqi Health Minister Saleh al-Hasnawi described the latest WHO report as "very sound" and said the survey indicated "a massive death toll since the beginning of the conflict."

"I believe in these numbers," he told the conference call.

The White House said it had not seen the study, but mourned the deaths of Iraqi civilians.

"The unmistakable fact is that the vast majority of these deaths are caused by the willful, murderous intentions of extremists committed to taking innocent life," said White House spokesman Tony Fratto.

"It is also beyond dispute that more Iraqi citizens would be condemned to death and oppression if they were abandoned by America and our coalition partners."

The U.S. Department of Defense said enormous precautions were taken to avoid civilian deaths and injuries.

More than half of the violent deaths documented in the WHO report occurred in Baghdad.

An average of 128 Iraqis suffered violent deaths every day in the first year following the invasion. The next year, an average of 115 were killed daily and 126 died from violence each day in the third year after the war started.

Estimates of Iraq's civilian deaths have been hampered by the lack of a well-functioning death registration system, the WHO said.

Some 3,915 U.S. and 174 British forces have died since the war began. Between 4,900 and 6,375 Iraqi military personnel are thought to have died, though no reliable official figures have been issued since new security forces were set up in late 2003.

Death tolls have fallen in recent months as the number of violent attacks in Iraq has declined.