Helicopter gunships and troops with small and heavy arms blasted a valley in southern Afghanistan on Wednesday as local and Nato forces launched a huge offensive against hundreds of Taliban insurgents, many of whom broke out of jail last week, Reuters reports from Arghandab.

The defence ministry in Kabul said 20 Taliban guerrillas were killed in a Nato airstrike and two Afghan army officers also died in the operation in Arghandab district. The ministry said three Taliban group leaders were killed further south.