NEW YORK — A controversial new study contends nearly 655,000 Iraqis have died because of the war, suggesting a far higher death toll than other estimates.

The timing of the survey's release, just a few weeks before the U.S. congressional elections, led one expert to call it "politics."

In the new study, researchers attempt to calculate how many more Iraqis have died since March 2003 than one would expect without the war. Their conclusion, based on interviews of households and not a body count, is that about 600,000 died from violence, mostly gunfire.

The study by Dr. Gilbert Burnham, of the Johns Hopkins Bloomberg School of Public Health, and others is to be published today on the Web site of The Lancet, a medical journal.

An accurate count of Iraqi deaths has been difficult to obtain, but one respected group puts its rough estimate at closer to 50,000. And at least one expert was skeptical of the new findings.

"They're almost certainly way too high," said Anthony Cordesman of the Center for Strategic & International Studies in Washington.

The work updates an earlier Johns Hopkins study — that one was released just before the November 2005 presidential election. At the time, the lead researcher, Les Roberts of Hopkins, said the timing was deliberate. Many of the same researchers were involved in the latest estimate.

Speaking of the new study, Burnham said the estimate was much higher than others because it was derived from a house-to-house survey rather than approaches that depend on body counts or media reports.

A private group called Iraqi Body Count, for example, says it has recorded about 44,000 to 49,000 civilian Iraqi deaths. But it notes that those totals are based on media reports, which it says probably overlook "many if not most civilian casualties."

For Burnham's study, researchers gathered data from a sample of 1,849 Iraqi households with a total of 12,801 residents from late May to early July. That sample was used to extrapolate the total figure. The estimate deals with deaths up to July.

The survey participants attributed about 31 percent of violent deaths to coalition forces.

BAGHDAD, Iraq — A massive fire at an ammunition dump at a U.S. base in southern Baghdad was sparked by a mortar round fired by insurgents, which set off a series of explosions from detonating tank and artillery shells that shook buildings miles away, the U.S. military said Wednesday.The 82mm round was fired from a nearby residential area and hit Forward Operating Base Falcon around 10:40 p.m. Tuesday, spokesman Lt. Col. Jonathan Withington said.There were no injuries reported, and Withington said the attack had no strategic effect.

ABUJA, Nigeria — OPEC has agreed to trim global oil production by 1 million barrels a day to boost prices, and its members were discussing how to share the cut, the cartel's president said Wednesday."The cut itself is agreed," said Nigerian oil minister and OPEC president Edmund Daukoru.Daukoru told reporters after a Cabinet meeting in the Nigerian capital that the cuts would begin at the end of the month and said members of the producing cartel were "nearing consensus" on how to share the cuts.Some analysts had been skeptical that members of the Organization of Petroleum Exporting Countries were willing to voluntarily sell less oil right now — especially its largest producer, Saudi Arabia — given that prices are twice as high as they were three years ago even after a recent 25 percent decline.