KABUL, Afghanistan — Afghan officials said Monday that at least 21 civilians were killed in a NATO airstrike in a southern province that borders Helmand, where thousands of coalition troops are taking part in an offensive in and around the town of Marja.
NATO said the incident in Uruzgan province, which occurred Sunday, was under investigation. It said U.S. Army Gen. Stanley A. McChrystal, the commander of all Western forces in Afghanistan, had already conveyed "sorrow and regret" to President Hamid Karzai.
A statement from NATO's International Security Assistance Force confirmed that "airborne weapons" were used against a convoy believed to be carrying insurgents on their way to stage an attack.
But arriving ground forces found women and children at the scene, the military said. It did not say whether any fighters were present as well.
NATO did not give an estimate of the number of dead, but Afghanistan's Interior Ministry said 21 bodies had been found and two other people were missing. Spokesman Zemari Bashary said about a dozen other people were hurt.
The airstrike was not related to the campaign in Marja, but the size and scope of that offensive have already stirred fears for civilian safety. NATO said at least 16 civilians had been accidentally killed by Western troops in the offensive, which was in its 10th day on Monday.
Western commanders have promised to take all possible measures to safeguard civilian lives during the assault, and McChrystal issued rules of engagement last summer making the safety of noncombatants the top priority.