At least four alleged militants were killed in an operation by security forces conducted overnight in Upper Orakzai Agency, officials said on Tuesday. Security forces also shelled two militant hideouts and destroyed them overnight. Meanwhile, two militants and one National Lashkar volunteer killed in an armed clash in Khyber Agency on late Monday. Officials said the clash between lashkar and terrorists took place in Khyber Agency Tehsil Landi Kotal.