At least 21 militants loyal to the Islamic State (IS) militant group were killed over the past 24 hours in Afghanistan's Nangarhar province, the internal ministry said on Sunday.According to a statement by the ministry, 13 more IS fighters were injured and several hideouts of the armed outfit destroyed during the operations in Achin district.The IS group has yet to make comment.Achin and the neighbouring Kot district have been regarded as the hotbed of IS militants in the eastern part of Afghanistan.Operations of the government forces against IS have been continuing over the past several months in the mountainous districts along the border with Pakistan's tribal areas but the ultra-extremist militant group is still active in the area.