Provincial police say the incident occurred on Wednesday night near the town of Mehtar Lam. Shots fired from NATO helicopters killed over 200 sheep belonging to local shepherds.
The sources told reporters that NATO troops claim they were targeting Taliban warriors. The alliance has not commented on the incident.
If the slaughtering of the animals is proven, local authorities will demand that the NATO pilots pay the herdsmen around $50,000 in compensation. The price of one sheep in Afghanistan is between $200 and $300 depending on its size.
Afghanistan's government has been increasingly critical this year of U.S.-led strikes that have led to major civilian losses. On November 3, coalition air strikes and gunfire killed 37 civilians during a wedding party in south Afghanistan's Kandahar province. U.S. forces said they were responding to an attack from gunmen.