WASHINGTON -- The first American soldier killed during the assault in Afghanistan this month may have been hit by U.S. rather than enemy fire, the Pentagon said Friday in a report on some of the war's deadliest accidents.

Army Chief Warrant Officer Stanley L. Harriman of Wade, N.C., was originally believed killed in an enemy mortar attack March 2 at the opening of the offensive against al-Qaida fighters regrouping in the Shah-e-Kot valley.

War commander Gen. Tommy Franks said Friday he had asked for an investigation after learning an AC-130 gunship reported hitting an enemy convoy in the same region at about the same time.

"I put the two things together and said ... we need to find out the facts ... to see if there is any connection," Franks told a Pentagon press conference.

Harriman, 34, was posthumously awarded the Silver Star and the Purple Heart, presented to his father, Buzz Harriman, a retired Army major.

Freedom fighter

The younger Harriman's widow, Sheila, said Friday, "He was still fighting for his country. ... Regardless of how he was killed, it will never change the fact that he was over there fighting for our freedom. He's still a hero."

Franks' disclosure came as part of report making public some of the findings on 10 cases of friendly fire, civilian casualties and damage to property since the war in Afghanistan began nearly six months ago.

The report said U.S. communications and procedural errors resulted in some of the accidents but the United States was not at fault in others. Still other cases remain under review.

The report held to the Pentagon's earlier assertions that there were no errors in targeting in a Jan. 23 raid on two suspected enemy compounds in Hazar Qadam. U.S. troops killed 16 people and captured 27, none of whom turned out to be either al-Qaida or Taliban. The 27 were later released.

"The fact of the matter is that this is a war," Franks said.

In other incidents the report said:

A United Nations convoy was damaged by debris from bombing in November, partly because the convoy was "not traveling on the days for which it had requested and received clearance."

The second bombing in 10 days in October of Red Cross warehouses was still under investigation.

The buildings were in a compound also being used by the Taliban and were bombed Oct. 16 after the Red Cross failed to include them on a list of its facilities, the report said without making a conclusion on another bombing of the site Oct. 26.