The International Security Assistance Force said in a written statement the casualty reports came from the provincial governor in the wake of anti-insurgency operations in the area.
"We take allegations of civilian casualties very seriously," U.S. Army Col. Patrick Hynes, head of the ISAF operations center, said. "We are conducting an immediate assessment of these allegations and will report our findings."
Details on the reported deaths were not revealed. The ISAF said its information on the operations, which took place at night in a remote area, were that 36 armed insurgents were killed.