The US military authorities are still insisting they struck a legitimate military target in western Iraq last week, despite new evidence that many of those who died in the attack were part of a wedding party.
A video obtained by the Associated Press television service appears to show a wedding celebration at the scene where the attack later took place, killing up to 45 people.
The US authorities had earlier said the target of the raid was a safe house used by foreign fighters.
This morning, a senior official in Baghdad said the US military still did not believe there was a wedding underway when the attack was carried out early the following morning.
Meanwhile, the British Foreign Office says two British civilians have died in a bomb explosion in Baghdad.
Officials could not confirm if they were among those killed when a car exploded outside coalition headquarters. Four people died in that attack.