Abdul Razaq, the Provincial army commander said the strike took place on Monday morning in Logar province's district of Baraki Barak, about 50km east of Kabul. He said five troops were also wounded as an army checkpoint was hit.
Other Afghan officials also reported the strike, though they gave a slightly different number of casualties. But a report by AFP news summarized the death toll at at least 10 people.
The Taliban group is active in the area, and fighters are known to transit through Baraki Barak.
Mohammad Rahim Amin, the District governor said the strike was likely a mistake, due to bad coordination.
He said two US helicopters had attacked the checkpoint, which caught fire.
A US military official in Afghanistan, speaking on condition of anonymity in line with regulations, said they were aware of an incident in Logar and were investigating it.
A similar NATO air strike in the area in December killed five civilians and wounded six others.
