Washington ? The U.S. military death toll after 10 months of engagement in Iraq reached 500 on Saturday, roughly matching the number of U.S. military personnel who died in the first four years of the U.S. military engagement in Vietnam.

The death toll in Iraq, which had been 497 on Friday, rose by three when a remote-controlled bomb made of two artillery rounds packed with explosives detonated beneath a Bradley fighting vehicle carrying five American soldiers and at least two Iraqi civil defense personnel in cane fields north of Baghdad.

Military officials said the explosion occurred near the town of Taji during a search for buried land mines and roadside bombs, which have previously claimed lives in the area. They expressed surprise that the Bradley was destroyed in the blast, according to Washington Post correspondent Daniel Williams in Baghdad.

The same cumulative toll of 500 deaths was reached in Vietnam in 1965, the year when the U.S. deployment there rose from 23,300 to 184,300 troops. In Iraq, in contrast, the United States is rotating forces with the goal of reducing the total number from 130,000 to 105,000 by June and also sharply scaling back its military presence in Baghdad.

On Saturday, Brig. Gen. Mark Kimmitt, a military spokesman in Iraq, dismissed the significance of reaching the threshold of 500 deaths. “I do not believe that any arbitrary … figure is going to cause any soldiers to lose their will or their focus,” Kimmitt said.

But Steven Kull, director of the University of Maryland’s Program on International Policy Attitudes, said the rising death toll could eventually undermine the popularity of President Bush and support for his handling of the conflict, even if it did not stoke support for an American pullout.

Noting that many Americans polled before the war began said they anticipated roughly 1,000 combat deaths, Kull said, “There are no signs of the population going toward a Vietnam-style response, in which a large minority or even a majority says, ‘pull out.'” That goal has steady support among only 15 percent to 17 percent of the public.

He said the public continued to be led by a consensus among elites in support of continued U.S. military engagement in Iraq. “There is a lot of controversy about whether we should have gone in,” but even among the Democratic presidential candidates, only Rep. Dennis J. Kucinich of Ohio favors a U.S. withdrawal, Kull noted.

Nancy Weaver, widow of U.S. Army Chief Warrant Officer Aaron Weaver, holds her children, Austin, 10, and Savannah, 1, after a memorial service for her husband at Citrus High School in Inverness, Fla. Weaver died last week in a helicopter crash in Iraq. He had survived cancer and the 1993 battle of Mogadishu, recounted in the movie Black

Most Americans see little alternative to staying in Iraq, given the risks of creating a breeding ground for terrorism if U.S. troops leave too soon. Nonetheless, he said, the rising death toll has increased the “cost” of the war at the same time its benefits “have gotten muddier” because of the failure to find weapons of mass destruction or clear Iraqi links to al-Qaida terrorists.

As a result, nearly half of those polled already say the war has not been “worth it,” and support for Bush’s handling of the war has dropped from 75 percent in April to 47 percent in October; it rose to 58 percent in December, after the capture of former Iraqi president Saddam Hussein, Kull noted.

The populous states of California, Texas and Pennsylvania have experienced the most deaths of their citizens in Iraq, totaling 123, according to statistics compiled by military officials and news agencies. But the death toll has been proportionally highest in American Samoa and the lightly populated states of Montana, Wyoming, North and South Dakota, and Delaware, plus the District of Columbia.

The cities that have lost the most citizens are Los Angeles, Buffalo, Houston and San Diego; the U.S. military base to suffer the highest death toll is in Fort Campbell, Ky. Allied forces in Iraq have reported a total of 90 deaths, with 55 of those from Britain.

The U.S. military attributes 346 of the U.S. deaths to hostile action and 154 to nonhostile causes. At least 2,497 military personnel have been wounded in Iraq.

During the 14-year U.S. engagement in Vietnam, a total of 58,198 troops were killed, including 47,413 combat deaths and 10,785 “nonhostile” deaths.

Iraqis look at a bomb crater along the road near the Iraqi town of Taji, where a roadside bomb killed three U.S. soldiers and two Iraqi civil defense troopers when a Bradley Fighting Vehicle hit the explosive device. Two Americans also were wounded Saturday in the attack.