International forces accidentally killed two Afghan boys during an operation in southern Afghanistan, the US-led coalition said.
Marine Gen. Joseph Dunford, the commander of US and allied forces in Afghanistan, offered his "personal apology and condolences to the family of the boys who were killed" and said the coalition takes full responsibility for the deaths.
A statement issued by the coalition says the boys were killed Thursday when coalition forces fired at what they thought were insurgent forces in the Shahid-e Hasas district of Uruzgan province.
It says a joint Afghan-NATO investigation team visited the location yesterday and met with local leaders.
The killing of civilians by foreign forces has been a major source of tension with the Afghan government throughout the nearly 12-year-old war.
According to a recent report by the United Nations, 2,754 Afghan civilians were killed last year, down 12 percent from 3,131 in 2011.
But the number killed in the second half of last year rose, suggesting that Afghanistan is likely to face continued violence as the Taliban and other militants fight for control following the impending withdrawal of US and allied combat forces.
The UN said the Taliban and other insurgents were responsible for 81 per cent of the civilian deaths and injuries last year while 8 per cent were attributed to pro-government forces.
The remaining civilian deaths and injuries could not be attributed to either side.
The number of casualties blamed on US and allied forces decreased by 46 per cent, with 316 killed and 271 wounded last year. Most were killed in US and NATO airstrikes, although that number, too, dropped by nearly half last year to 126, including 51 children.