The boys were shot dead by Australian soldiers during an operation in the southern province of Uruzgan, International Assistance Force (ISAF) Commander General Joseph Dunford said in a statement on Saturday.

Afghan officials said the two, aged seven and eight, had been tending cattle at the time. The soldiers opened fire, killing the boys, after insurgents operating in the area shot at a helicopter carrying Australian soldiers.

"I offer my personal apology and condolences to the family of the boys who were killed," Dunford said. "The boys were killed when coalition forces fired at what they thought were insurgent forces."

ISAF said a joint Afghan-ISAF team on Saturday visited the district, Shahidi Hassas, to investigate and meet with local leaders.

"I am committed to ensuring we do the right thing for the families of those we harmed, as well as for the community in which they lived. We take full responsibility for this tragedy."

Reasons remain unclear

A spokesman for provincial governor Amir Mohammad Akhundzada told the Reuters news agency that the boys had been listening to a radio, adding that the reasons they were shot at remained unclear.

The move is likely to exacerbate tensions between ISAF and the government of Afghan President Hamid Karzai. Past civilian deaths caused by ISAF, particularly those that involve children, have stoked anger and opposition to the coalition operations.

A NATO air strike requested by Afghan forces on February 13 resulted in the deaths of 10 people, including five children and four women. The development led to Karzai banning his forces from calling in foreign airstrikes.

Most of the 1,550 Australian soldiers deployed in Afghanistan are based in Uruzgan. They are mainly occupied with the training of Afghan soldiers ahead of the planned withdrawal of foreign troops next year.

rc/ccp (AFP, dpa, Reuters)