A US military investigation has concluded that at least 33 civilians, including a dozen children, were killed in an air strike August 22 in western Afghanistan, a summary of the findings released Wednesday said.
   
The investigation by Brigadier General Michael Callan also found that US forces acted in self-defense, in keeping with their rules of engagement and the law of war.
   
The toll was far higher than the five to seven civilians that the military has long insisted were killed in the fighting, but well short of the 90 civilian dead claimed by the Afghan government.
   
"Our investigation determined approximately 55 persons were killed (33 civilian and 22 anti-coalition militants)," the executive summary of the investigation report said.
   
Investigators were able to identify or discern the bodies of eight men, three women and 12 children in videos of bodies laid out for burial in the village mosque the day after the fighting, the report said.
   
The incident has brought angry recriminations from Afghan President Hamid Karzai and added to fears that support for the US military presence in Afghanistan is being undermined by repeated cases of civilian casualties.
   
But the Callan report defended the actions of the US and Afghan forces involved in the incident.
   
"The use of force was in self-defense, necessary and proportional, based on the information the on scene commander had at the time," it said.
   
The report said the US and Afghan forces staged the raid on the village of Azizabad on the basis of "credible" intelligence that a militant commander and 20 to 30 fighters were holding a shura, or meeting, there.
   
When they came under fire, US and Afghan forces "demonstrated due dilligence in engaging positively identified hostile ACM (anti-coalition militants) with close air support and small arms."
   
The commander at the scene worked with the crew of an AC-130H gunship to pick out to identify "legitimate targets," it said.
   
"Unfortunately and unknown to the US and Afghan forces, the ACM chose fighting positions in close proximity to civilians," the report said.
   
"US and Afghan forces did not commit any violations of the law of war or rules of engagement," it said.
   
An initial US military investigation found that 30 insurgents and two women and four children were killed.
   
But General David McKiernan, the top US commander in Afghanistan, asked for another investigation on September 7, after cellphone video came to light showing numerous women and children among the dead.
   
The Callan investigation concluded that the video was authentic and villagers had laid out the bodies for burial in the village mosque the day after the attack.
   
But lists of dead villagers obtained by Afghan and UN officials that showed that 90 civilians were killed "are unsubstantiated," the report said.
   
It said the Afghan investigation relied on "inconsistent villager statements" and evidence tainted by witnesses' "financial, political and/or survival agendas."
   
"Additionally, no forensics was conducted and their claims were not supported by graves, video or intelligence," it said.
   
The report said its conclusions were based on 28 interviews, reviews of documents, and 11 videos.
   
Callan recommended joint investigations into future cases involving disputed civilian casualties as well as greater cooperation with international and non-governmental organizations.
   
"We are deeply saddened at the loss of innocent life in Azizabad," said General Martin Dempsey, the acting head of the US Central Command.
   
"We go to great lengths to avoid civilian casualties in Afghanistan in all our operations, but as we have seen all too often, this ruthless enemy routinely surround themselves with innocents," he said in a statement.