UNITED NATIONS — A vast discrepancy between a United Nations accusation that American-led forces killed 90 civilians in one recent Afghanistan battle and an American investigation that concluded no more than 7 civilians were killed is calling into question the methodology of the two competing investigations.

U.S. Army investigators said in a report released yesterday that between 30 and 35 militants were killed in the battle last month, including a top Taliban commander, Mullah Sadiq. The report concluded that the military action, which included an air bombardment, was justified, as the coalition forces came under intense fire from militants.

The investigation by the American-led Combined Joint Task Force 101 determined that “five to seven civilians were killed” in the battle near Azizabad, in western Afghanistan’s Herat province, during pre-dawn hours of August 22.

That casualty figure is at odds with a contention by Afghanistan’s President Karzai, which was bolstered last week by an investigation conducted by the United Nations. “90 civilians were killed” in the battle, “including 60 children, 15 women, and 15 men,” an August 26 statement released by the U.N. special envoy in Afghanistan, Key Eide, concluded.

“The U.N. continues to stand by its finding,” and specifically that “women and children were among the many casualties in that incident,” a U.N. spokeswoman, Marie Okabe, told The New York Sun yesterday.

The U.N. estimate – by far the highest civilian casualty figure in the five-year war in Afghanistan – was invoked immediately by Russia, which was under intense scrutiny for its own military actions. As the Security Council discussed fast-unfolding events in Georgia last week, Russian diplomats used the U.N. figures in a failed attempt to issue a council statement denouncing the American-led action in Afghanistan.

According to diplomats present at the closed-door consultation, the American U.N. ambassador, Zalmay Khalilzad, urged council members to wait until American investigators published their final conclusions about the battle. Diplomats at the American U.N. mission yesterday declined to denounce the U.N. findings, but stressed they stand by the Pentagon’s findings. Asked about the U.N. investigation, a spokesman for task force 101, Lieutenant Richard Ulsh, who spoke by telephone from Bagram airfield, said “We did our investigation, we can’t speak to theirs.”

American “investigators determined the range in the casualty numbers by observation of the enemy movements during the engagement as well as on-site observations immediately following the engagement,” the Pentagon said in a statement yesterday. “The investigating officer took statements from more than 30 Afghan and U.S. participants” in the battle, it said, adding the officer “also reviewed reports made by ground and air personnel during the engagement; video taken during the engagement; topographic photo comparisons of the area before and after the event, including analysis of burial sites; reports from local medical clinics and hospitals; intelligence reports; and physical data and photographs collected on the site.”

The U.N.’s Mr. Eide, by contrast, described a “destruction from aerial bombardment,” which “was clearly evident with some 7-8 houses having been totally destroyed and serious damage to many others. Local residents were able to confirm the number of casualties including names, age, and gender of the victims.”

Military spokesmen caution that local populations often support insurgents, and therefore their accounts cannot always be relied on to determine casualty figures. Beyond “the testimony of eyewitnesses and others,” Mr. Eide cited no external support for his claim that “convincing evidence” led to his conclusion about the civilian casualties.