The occupation soldier was wounded when he was attacked by resistance fighters west of Baghdad on Monday morning.
No further details were available.
In Samarra, scenes of devastation dotted the town after fierce US attacks in which senior police and hospital officials said at least eight civilians were killed and dozens wounded.
American troops said on Monday that 54 resistance fighters had been killed in clashes on Sunday.
But our correspondent and other news agencies quoted hospital sources and Samarra residents as saying that the US fire killed eight people, all civilians.
Samarra hospital accident and emergency department anaesthetist Bassam Ibrahim said “we received the bodies of eight civilians, including a woman and a child”.
It was not immediately clear whether the dead civilians included two Iranians who were found dead in their bus when on a visit to holy sites.
Hospital director Abd Tawfiq said “more than 60 people wounded by gunfire and shrapnel from US rounds are being treated at the hospital”.
Colonel Fredrick Rudesheim said the toll was 46, repeating an earlier number. He added it was not a firm toll, based on a body count, but an estimate based on interviews with all the soldiers involved.
The attacks on US troops were "coordinated", and targeted two convoys transporting new Iraqi currency as part of an exchange scheme to replace old notes, added Rudesheim.
AFP correspondents saw a civilian bus completely burned out,30 metres from the main entrance to the town’s hospital.
The correspondents were shown two Iranian passports, said to belong to the visitors killed in the bus. Nine others, also Iranians, were wounded, said the police guard outside the hospital.
Iranian officials expressed concern over the incident and called for an immediate investigation into the attack.
Tehran warned the incident could
further harm Iran-US ties
Reda Yosofyan, a member of the Iranian parliament's national security and foreign policy commission, said Washington was directly responsible for the Iranians' death.
"This event will evoke even more distrust between Iran and the US," he told Aljazeera.net. Yosofyan also called on the US-appointed Iraqi Governing Council to investigate the incident and report the findings to Tehran.
But Council spokesman Hamid al-Kifai said he did not know of any Iranian deaths in the Samarra attack. "We cannot discuss anything which we do not know about," he told Aljazeera.net.
Yosofyan warned that such incidents might harm future ties between Baghdad and Tehran if they were not investigated.
When contacted by Aljazeera.net, a US military spokesman in Baghdad said they had no information on any Iranian deaths. In response to the toll he said, "I cannot respond to that because I do not have the details."
These are not the first Iranian casualties as a result of US fire since the Washington-led invasion of Iraq.
In the early days of the invasion, a stray missile landed near Iran's western border, injuring a number of civilians.
The town’s police chief Colonel Ismail Mahmud Muhammad said about 20 of the injured sustained their injuries while worshipping at a mosque during sunset prayers.
Two Iranian passports reportedly
belonging to victims of US attack
Resistance fighters who had attacked occupation forces had withdrawn when the Americans returned fire, said Muhammad.
Troops had done so indiscriminately with all weapons in their arsenal, he added.
“There was an attack and an exchange of fire between the Americans and the resistance lasting half an hour. The resistance withdrew, then bombardments started using all manner of weapons in all directions and without any discrimination,” said Muhammad.
He also said eight civilians were killed, including a child.
Shaikh Muhammad Abd al-Karim, in charge of security on the local municipal council, cited police reports that the clashes had begun when assailants attacked a US convoy delivering money to al-Rashid Bank.
"There were shots, and then a half-hour exchange with the
assailants, who then fled," he said.
"Then there was a massive US bombardment in which buildings, including mosques and schools, were hit by the Americans."
Abd al-Karim said that Apache helicopter gunships had opened fire during the bombardment of the built-up area, although flares carried by the assault aircraft could sometimes be mistaken for cannon fire.
The impact of a rocket could be seen on one of the outer walls of al-Shafi mosque, nearly 50 metres from the hospital. Its windows had been shattered by the blast.
Ali Abd Allah Amin, 12, who was being treated at the hospital with his five-year-old brother for wounds sustained in the mosque, said their father had been killed in the firing.
In another street in the town where a US convoy came under attack earlier in the day, a car parked outside a chemist’s shop had been completely flattened, apparently by a tank.