The airstrike hit North Waziristan, which borders Afghanistan. Also Monday, Pakistan said it was on the verge of a major victory – arresting Swat militant chief Maulana Fazlullah.
Such airstrikes are launched regularly on the mountainous tribal region bordering Afghanistan, a stronghold for the Taliban, despite official Pakistani objections. Monday's came as the Pakistani government announced the impending arrest of a top militant, Swat Taliban leader Maulana Fazlullah.
The Associated Press put the death toll at four, and noted that Pakistan and the US continue to be at odds over the strikes.
Monday's attack took place about 1.5 miles (3 kilometers) from the town of Mir Ali in North Waziristan, killing four people, two officials and witnesses said. The officials spoke on condition of anonymity, saying they need to remain unnamed to do their job effectively.
The identities of the victims were not known.
Witnesses Ikramullah Khan and Mohammad Salim said the missile hit a vehicle with blacked-out windows — a style associated with Taliban fighters in the region.