Australian Prime Minister Julia Gillard has said that the deaths of two children in Afghanistan are a tragedy but it will take time to find out exactly what happened.
The boys, aged seven and eight, died on Thursday morning as Australian soldiers fought back after an apparent Taliban attack in southern Uruzgan province.
"What we do know is there have been two children who have lost their lives. That is a genuine tragedy," Gillard told reporters in Sydney on Monday.
"The loss of life is tragic, the impact on families is tragic, and the impact on soldiers involved in the operation is tragic too," she said.
The Australian Defence force chief General David Hurley also offered his condolences to the families in Afghanistan.
Afghan President Hamid Karzai released a statement Sunday condemning the airstrike that killed the two boys.
Karzai said his heartfelt condolences went to the mourning families of the victims.
"The Afghan government has repeatedly stressed that the war on terrorism cannot succeed in Afghan villages and homes, but rather in its sanctuaries and safe havens outside our borders," the statement said.
Isaf apologised for the incident on Saturday, saying that coalition forces accidentally shot dead two boys on Thursday.
"It is with deep regret that the International Security Assistance Force announces that its forces were responsible for the unintended death of two young Afghan civilians during an operation Feb. 28 in Shahid-e Hasas District, Uruzgan Province," the statement from the Nato-led forces said.
"I offer my personal apology and condolences to the family of the boys who were killed," it quoted Isaf commander Gen. Joseph Dunford saying.
Isaf said the boys were killed when the coalition forces fired at what they thought were insurgent forces.