At least 16 people were killed and many others injured in a US drone attack in North Waziristan tribal region, the second strike in less than 10 hours, report said on Tuesday. The second US missile strike which killed four alleged militants hit a vehicle in the northwestern tribal area. A US drone fired four missiles on a vehicle carrying militants outside Miranshah, a senior security official said. At least four militants were killed in the attack, the official said. The strike took place in Qutabkhel village, a southern suburb of Miranshah, the main town of North Waziristan tribal district.