MIRANSHAH, Pakistan (Reuters) - Four Islamist militants were killed and five wounded in a missile attack by a suspected U.S. drone in Pakistan's North Waziristan tribal region on Thursday, security officials and witnesses said. The attack targeted the house of a tribesman, Rehman Wali, in the Mohammad Khel area, near the border with Afghanistan, where the militants were hiding. "Apparently three missiles were fired by the drone," a witness in the area told Reuters on condition of anonymity.