The US army has disputed the circumstances surrounding the killing of up to 45 people in Iraq's western desert.
Reports that the victims were part of a wedding party have sparked outrage as Washington struggles to contain a prisoner abuse scandal.
US Brigadier General Mark Kimmitt
Brig Gen Mark Kimmitt, deputy director of operations for the US military in Iraq, said the attack early yesterday targeted "a suspected foreign fighter safe house", 16 miles east of the Syrian border.
But Dubai-based Al Arabiyatelevision, quoting witnesses, said the raid on the village of Makr al-Deeb had targeted people celebrating a wedding and had killed at least 41 civilians.
Asked about reports of dozens killed, Brig Gen Kimmitt said: "We are not disputing the numbers you are hearing. We estimate that around 40 were killed. But we operated within our rules of engagement."
Arabiyashowed pictures of several shrouded bodies lined up on a dirt road. Men were shown digging graves and lowering bodies, one of a child, into the pits while relatives wept.
"We received about 40 martyrs today, mainly women and children below the age of 12," Mr Hamdy al-Lousy, the director of Qaim hospital, told Al Arabiya. "We also have 11 people wounded, most of them in critical condition."
Mr Hamdy
In Al Arabiya's report, a man who said he was from the village said: "They [US forces] hit two homes where the wedding was being held and then they levelled the whole village," he said. "No bullets were fired by us, nothing was happening."
Guests and relatives at Muslim weddings often fire guns in the air in jubilation. In July 2002, a US air strike on an Afghan wedding party killed 48 civilians. A report released by the US Central Command said the strike was justified because US planes had come under fire.
A US military statement said that during Wednesday's operation, "coalition forces came under hostile fire and close air support was provided". It said troops recovered numerous weapons, two million Iraqi and Syrian dinar, foreign passports and a satellite communications system.
Brig Gen Kimmitt said there were no indications the victims of the attack had been celebrating a wedding.