NATO-led forces in Afghanistan have offered condolences for eight young Afghan men killed in an air strike last week in eastern Kapisa province.

Army Brigadier Gen. Lewis Boone told reporters in Kabul that the aircraft dropped two bombs on the group which was carrying weapons and believed to be an imminent threat to coalition forces in the area.

Afghan President Hamid Karzai condemned the air strike and ordered U.S. and NATO forces to take more actions to prevent civilian casualties.

Local officials say the dead were between the ages of 6 and 14 with one being a mentally ill young man around 18 to 20 years old.

British Air Commodore Mike Wigston says the young men were “adult-sized” and he had no doubt they were carrying weapons. He says military examinations of photographs of the bodies puts them about 15 with one being older.

The issue of civilian casualties caused by coalition operations has long been a source of tension between President Karzai and NATO.

A United Nations report released earlier this month said more than 3,000 civilians were killed in 2011 – the worst death toll in the decade-long Afghan war.

Officials with the U.N. mission in Afghanistan said insurgents were responsible for 77 percent, or 2,300, of Afghan civilian deaths, and that the 410 deaths caused by foreign and local forces dropped by 4 percent.