At least six people were killed Tuesday when an unmanned US aircraft fired missiles at a vehicle in Pakistan\'s volatile north-western tribal region, a security official said. The official said a drone fired four missiles, destroying the vehicle. \"Three people were killed in the attack and we have reports that two of those dead were foreigners, but we have no idea about their nationalities,\" he said. The evening strike took place in the Hamzoni area of North Waziristan, which is located near the Afghan border and is one of seven tribal districts where al-Qaeda-linked Taliban rebels have hideouts. On Saturday, the Pakistan Foreign Ministry issued a statement saying these types of attacks were a violation of its sovereignty and territorial integrity, and in contravention of international law.