Updated

The U.S.-led coalition says 20 insurgents were killed after an airstrike and clashes in southern Afghanistan.

The coalition statement says the insurgents died in Kajaki district of Helmand province Wednesday after dozens of militants attacked a combined Afghan-coalition patrol.

There were no casualties among coalition and Afghan troops.

Southern Afghanistan is the center of the Taliban-led insurgency. A series of clashes in the same region on Tuesday killed 31 militants.

The region is also the largest opium producing area in the world. The U.N. says hundreds of millions of dollars from the illicit trade are used to fund the insurgency.