Six suspected militants were killed in a drone attack on a vehicle in Pakistan's tribal region of South Waziristan Monday, intelligence officials said. The Pakistani officials told CNN a drone fired two missiles at the vehicle. South Waziristan is on Pakistan's border with Afghanistan and the majority of drone strikes have been in areas in North and South Waziristan, the officials said. Intelligence experts say the areas are havens for militants. The United States normally doesn't comment on drone strikes but is the only country in the region known to have the ability to launch missiles from remote-controlled drones.