The US-led coalition said 20 insurgents were killed after an airstrike and clashes in southern Afghanistan. The coalition statement said the insurgents died in Kajaki district of Helmand province Wednesday after dozens of terrorists 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 terrorists. The region is also the largest opium producing area in the world. The UN says hundreds of millions of dollars from the illicit trade are used to fund the insurgency.