The US military has reprimanded six operators of an unmanned drone, which mistakenly attacked a civilian convoy in Afghanistan killing at least 23.
Warnings that the convoy was not an attacking force were ignored or played down, while the ground-force commander was not sure who was in the vehicles, an investigation found.
The deadly assault took place in Uruzgan Province in February.
Civilian deaths in strikes have caused widespread resentment in Afghanistan.
A Nato statement at the time said it was thought the convoy contained Taliban insurgents on their way to attack Afghan and foreign military forces.
However, troops then found "a number of individuals killed and wounded", including women and children.
A US military investigation said the order to attack was based on inaccurate information from the crew monitoring the convoy from an Air Force base in Nevada and on flawed analysis by Nato commanders.
The reports said poorly functioning command posts "failed to provide the ground-force commander with the evidence and analysis that the vehicles were not a hostile threat".
The commander of the international forces in Afghanistan, Gen Stanley McChrystal, said letters had been issued reprimanding four senior and two junior officers in Afghanistan.
He said: "Our most important mission here is to protect the Afghan people; inadvertently killing or injuring civilians is heartbreaking and undermines their trust and confidence in our mission.
"We will do all we can to regain that trust."
The botched strike happened despite Gen McChrystal's introduction of much tougher rules of engagement in a bid to minimise such casualties.