Australian soldiers in southern Afghanistan have shot dead two young Afghan boys.
The NATO-led International Security Assistance Force (ISAF) said the pair were mistaken for Taliban insurgents.
The boys aged under seven were tending cattle when they were killed on Thursday in Uruzgan province.
ISAF commander General Joseph Dunford apologised to the family of the boys and said the force took full responsibility for the tragedy.
In a statement he said the boys were killed when coalition troops fired at what they thought were insurgent forces.
General Dunford said that ISAF and Afghan investigators had already visited the village in the central province where the boys lived and met local leaders.
Australian Defence Force chief General David Hurley said soldiers from the Special Operations Task Group were conducting a routine liaison patrol when the incident occurred.
General Hurley said it was too early to know who was at fault in the deaths of the boys, AAP reports.
Provincial governor Amir Mohammad Akhundzada told AFP the insurgents had first shot at a helicopter carrying Australian soliders.
Civilian casualties caused by NATO-led forces have been one of the most contentious issues in the campaign against insurgents, often triggering widespread public anger.
Last month, 10 Afghan civilians, including five children, were killed by a NATO airstrike in Kunar province.
Following the attack, President Hamid Karzai barred Afghan forces from seeking air support from foreign troops in a bid to curb civilian casualties.