A U.S. military spokesman on Monday denied reports by local officials that a NATO airstrike killed 11 police and counter-narcotics agents in southern Afghanistan.

"There were no strikes conducted by U.S. or NATO forces in Helmand Province on 6 September," Col. Brian Tribus said in a statement. He said U.S. forces had conducted "kinetic strikes" in the Maiwand District of Kandahar Province on Sunday "to eliminate threats to the force."

An Afghan official, who spoke on condition of anonymity because he was not authorized to release information, had earlier said that a NATO airstrike in Helmand on Sunday killed the 11 during an operation to arrest drug smugglers.

He said four other counter-narcotics officers were wounded in the strike, which took place late Sunday outside Lashkar Gah, the provincial capital.

Nabi Jan Mullahkhail, Helmand provincial police chief, confirmed the airstrike but did not say who carried it out or give any other details.