At least six suspected militants were killed on Friday in a US drone strike near Pakistan-Afghan border in Khyber Agency.Security sources said the drone targeted a militant compound in the Nazyan district of Afghanistan's Nangarhar province, on the zero line bordering Khyber Agency. The drone strike killed six suspected militants while the compound was completely destroyed, Dawn online reported.The sources added that all the six "militants" belonged to the self-styled Islamic State (IS) group in Afghanistan.Till 2014, Naziyan district had been serving as a safe haven for the Mullah Fazllullah led Tehreek-i-Taliban Pakistan (TTP).According to security officials, militants based in the Nazyan district had planned the devastating attack on the Army Public School in Peshawar, which left over 150 children and teachers dead.