Kabul: An Afghan official says a group of children were playing with an unexploded mortar round when it blew up, killing four of them.

Police spokesman Mafuz Akbari says the deaths took place on Monday in a remote district controlled by the Taliban in the northern Kunduz province. He says another six children were wounded and brought to a hospital in the provincial capital.

Afghanistan is littered with unexploded munitions left over from decades of war, which along with roadside bombs kill or wound an estimated 140 people every month.