Brig. Gen. Wilson Shoffner says in a statement issued Tuesday that "based on information we received today, we feel it is prudent to investigate the airstrike our forces conducted in Kandahar" on Sunday.
An Afghan official, who spoke on condition of anonymity because he was not authorized to release information, said Monday that a NATO airstrike the night before in neighboring Helmand province killed the 11 during an operation to arrest drug smugglers.
Nabi Jan Mullahkhail, Helmand provincial police chief, confirmed the airstrike but did not say who carried it out.
The U.S. military has denied carrying out any airstrikes in Helmand on Sunday.