At least 12 militants loyal to the Islamic State (IS) were killed in a clash with security personnel in Afghanistan's Nangarhar province on Saturday, the media reported.The clash flared up in Kot district, leaving 10 militants injured, Xinhua reported.There were no casualties on security personnel, Ataullah Khogyani, spokesman for the Nangarhar provincial government, said.The IS fighters from the mountainous districts of Achin and Kot in the province, have been challenging Afghan security forces over the past several months.