Witnesses said warplanes had blasted dozens of people who were celebrating a wedding on Wednesday. Dozens of shrouded bodies were seen lined up on a dirt road.
But US occupation forces denied they had hit civilians.
Brigadier General Mark Kimmitt, deputy director of operations for the US military in Iraq, told Reuters the attack early on Wednesday targeted "a suspected foreign fighter safe house", 25km (16 miles) east of the Syrian border.
'They hit homes'
"US planes dropped more than 100 bombs on us," said an unidentified man claiming to be from the village.
"They hit two homes where the wedding was being held and then they levelled the whole village. No bullets were fired by us, nothing was happening," he added.
A local police official told AP news agency between 42 and 45 people had died as a result of the US attack.
The US has said it has no knowledge of the alleged attack, but says US forces did conduct a raid on a house in the border area. In Baghdad, a US military spokesman said the allegation was being investigated.
In July 2002, an American 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.