At least four people were killed and five others injured in a US drone strike in South Waziristan tribal region near Afghan border, sources said on Tuesday. The sources said that the unmanned aircraft targeted a vehicle in Baghar area. of Angur Adda , adding that more casualties were feared in the attack. The attack came at the time when the Pakistans army and the civil leadership are being harshly criticised in the backdrop of unilateral US operation in Abbottabad that led to killing of al-Qaeda Chief Osama bin Laden.