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 US-led forces are closely tracked and now total 1937.
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 UN news conference on Monday.
It builds on a study published in The Lancet, a British medical journal, last October, which concluded that 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 had 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.
Conflict deaths from small arms
are largely under-reported
Its 2005 small arms survey generally concludes that conflict deaths from small arms have been vastly under-reported in the past, not just in Iraq but around the globe.
The total number of direct victims of such weapons likely totalled 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.
The undercounting is due mainly to a paucity of hard data and an over-reliance by analysts on estimates based on government and media accounts of wars, "which are often inaccurate," according to the 2005 survey.
The number of indirect deaths around the world that can be blamed on small arms has also been underestimated, as these types of weapons typically trigger significant social disruption that leads to malnutrition, starvation, and death from preventable disease, according to the survey.
Depending on the nature of the conflict, small arms cause between 60% and 90% of all direct war deaths, the study said.
Following a formula developed at the United Nations, the small arms survey covers a broad range of hand-held arms, ranging from pistols and rifles to military-style machine guns, small mortars and portable anti-tank systems.
The small arms survey covered a
broad range of hand-held arms
The survey's release coincided with the opening of a weeklong UN conference intended to assess progress on a UN action plan for cracking down on the illicit global trade in small arms, adopted in 2001.
While worldwide public attention is riveted on the devastating potential of biological, chemical and nuclear weapons, small arms typically carried by a single individual "are the real weapons of mass destruction," said Ambassador Pasi Patokallio of Finland, the conference's chairman.
Heavy concentrations of small arms in a region are often enough to fuel a conflict, the small arms survey said.
In the tense Middle East, for example, private gun ownership is widespread and on the rise, and "representatives of several governments have expressed concern that gun violence is becoming a major threat to public safety and a source of regional instability," the survey reported.
It estimated that 45 million to 90 million small arms were in the hands of civilians across that region.