The public database Iraqi Body Count, by comparison, estimates that between 22,787 and 25,814 Iraqi civilians have died since the March 2003 invasion, based on reports from at least two media sources.

No official estimates of Iraqi casualties from the war have been issued, although military deaths from the U.S.-led coalition forces are closely tracked and now total 1,937.

The new estimate was compiled by the Geneva-based Graduate Institute of International Studies and published in its latest annual small arms survey, released at a U.N. news conference.

It builds on a study published in The Lancet, a British medical journal, last October, which concluded there had been 100,000 "excess deaths" in Iraq from all causes since March 2003. That figure was derived by conducting surveys of Iraqi mortality data during the war and comparing the results to similar data collected before the war.

Britain's government rejected The Lancet's conclusions shortly after their publication.

The Swiss institute said it arrived at its estimate of Iraqi deaths resulting solely from either combat or armed violence by re-examining the raw data gathered for the Lancet study and classifying the cause of death when it could.

Its 2005 small arms survey generally concludes that conflict deaths from small arms have been vastly underreported in the past, not just in Iraq but around the globe.

The total number of direct victims of such weapons likely totaled 80,000 to 108,000 during 2003, for example, compared to earlier estimates by other researchers of 27,000 to 51,000 deaths from small arms that year.