The program has killed a number of top militant commanders, including al-Qaida's then-No. 2, Abu Yahya al-Libi, who died in a drone strike in June.
Badruddin Haqqani, who has been described as the day-to-day operations commander of the Haqqani network, was killed by a drone attack in August. The Haqqani network has been blamed by the U.S. for carrying out some of the highest-profile attacks against American and NATO troops in Afghanistan.
Mahsud reported from Dera Ismail Khan. Associated Press writers Asif Shahzad and Munir Ahmed in Islamabad, Rasool Dawar in Peshawar and AP Intelligence Writer Kimberly Dozier in Washington contributed to this report.
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