KABUL: A string of roadside bomb attacks killed six civilians and wounded five children in insurgency-hit Afghanistan, authorities said on Sunday. Six civilians were killed in two separate bomb explosions in the southern province of Helmand on Saturday, the interior ministry said in a statement. They were killed when they drove over the devices, it said, blaming the attacks on insurgents. In a separate but similar bomb blast five children were wounded in Herat province, in the west of the country, it said.