The findings from Amnesty come as the US intensifies its air campaign against Islamic State targets, especially around the Iraqi city of Mosul, amid what US officials hope will be a decisive victory against the militant group. But more than two years after air operations began against the group, the Obama Administration is forced to contend with a growing roster of reported civilian casualties.
While human rights groups say that Russian and Syrian air attacks are now responsible for the vast majority of deaths in Syria, Centcom has received around 250 allegations of civilian casualties in Iraq and Syria since 2014. Officials have completed 62 investigations, concluding that 55 civilians were killed across the two countries.
"Amnesty International is concerned that Centcom appears to be significantly underestimating the extent to which the operations it directs have caused harm to civilians and damage to civilian objects," the group said in its memo.
Amnesty said it conducted its own investigations into the 11 incidents, sifting through social media and activist reports and, when possible, interviewing eye witnesses or relatives of the alleged victims.
"We think this was pretty robust under the circumstances," Sammonds said.
The group has also asked for details about what information Centcom has used and has disregarded when looking into allegations. Officials sometimes use local reporting and social media images and video when conducting official investigations, but sometimes rely mainly on military and intelligence information.
Amnesty is also urging the Obama administration to overhaul its investigation process, which has not provided full details to the public. Several completed investigations have been made public in a redacted form, but most have not beyond a summary of their conclusions.
Jacques said the command is committed to transparency. "We are working to release the assessment findings of the remaining closed allegations as soon as possible," he said.