The three missiles were fired minutes apart at a moving vehicle in the Marsi Khel area in North Waziristan, said two intelligence officials who confirmed the death toll on condition of anonymity because they were not authorized to speak on the record.
North Waziristan has long been a haven for militant networks battling American and NATO forces across the border in Afghanistan. In recent months, it has become something of a sanctuary for Pakistani Taliban leaders who have fled an army offensive in their previous stronghold, South Waziristan.
The Pakistani Taliban, while linked to the Afghan Taliban and al-Qaida, have primarily directed their attacks at targets inside Pakistan, making them a priority for the army.
The Pakistani army has held off on waging an offensive against the other networks that are based in North Waziristan, despite U.S. pressure. In the meantime, the U.S. has used missiles to target militant hide-outs there dozens of times in recent months.
In mid-January, Pakistani and U.S. officials said they believed a missile strike had killed Hakimullah Mehsud somewhere along the border of North and South Waziristan. But last week, Pakistani officials said they had reversed that assessment, and over the weekend two videos appeared suggesting Mehsud was still alive. In one of them, he says he is speaking on April 4 and denies the "propaganda" that he'd been killed.
Pakistan officially protests the strikes as violations of its sovereignty, but is believed to secretly aid them. The U.S. rarely discusses the drone-fired strikes, a covert program.
U.S. Central Command chief Gen. David Petraeus was in Pakistan on Monday meeting with Pakistani army chief Gen. Ashfaq Parvez Kayani. According to an army statement, the two "discussed matters of professional interest."
Also Monday, Pakistani army commandos backed by artillery and mortar fire killed 18 militants in Bajur, a tribal region where the military had twice declared victory over Taliban insurgents.
Local administrator Iqbal Khattak said troops surrounded militant hide-outs in Ghundo village near Khar, Bajur's main town. The commandoes staged the deadly raid after using mortars and heavy artillery to hit the sites.
Pakistan's paramilitary forces spearheaded an offensive in Bajur in fall 2008. Although on two occasions the military has said the Afghan border area is cleared, sporadic violence still occurs.
Access to the tribal regions is restricted, making it difficult to independently verify the information.