Baitullah Mehsud (Pashto,Urdu: byt llh mHswd); c. 1972 - c. 5 August 2009) was a leading militant in Waziristan, Pakistan, and the leader of the Tehrik-i-Taliban Pakistan (TTP). He formed the TTP from an alliance of about five militant groups in December 2007. He is thought by U.S. military analysts to have commanded up to 5,000 fighters and to have been behind numerous attacks in Pakistan including the assassination of Benazir Bhutto which he and others have denied. Disagreement exists over the exact date of the militant's death.

On 28 December 2007 the Pakistan government claimed that it had strong evidence regarding Baitullah Mehsud as the man behind the assassination of former Prime Minister Benazir Bhutto on 27 December 2007. The Pakistani government released a transcript it asserted was from a conversation between Baitullah Mehsud and Maulvi Sahib (literally "Mr. Cleric"). According to the transcript Maulvi Sahib claimed credit for the attack, Baitullah Mehsud asked who carried it out, and was told, "There were Saeed, the second was Badarwala Bilal and Ikramullah was also there."  The translation released from Agence France Presse differed slightly from the translation from the Associated Press. According to the transcripts Baitullah Mehsud says he is at, "Anwar Shah's house", in Makeen or Makin. The Agence France Presse transcript identifies Makeen as a town in South Waziristan.  Subsequently, both Agence France Presse and NDTV released an official denial by Mehsud's spokesman in which he said that Mehsud had no involvement in the attack, that the transcript was "a drama", that it would have been "impossible" for militants to penetrate the security cordon around Bhutto, and that her death was a "tragedy" which had left Mehsud "shocked". Mehsud's spokesman was quoted as saying: "I strongly deny it. Tribal people have their own customs. We don't strike women."  In an address to the nation on 2 January 2008, Pakistani President Pervez Musharraf said that he believed Maulana Fazlullah and Baitullah Mehsud were prime suspects in the assassination of Bhutto.  On 18 January 2008, The Washington Post reported that the CIA has concluded that Mehsud was behind the Bhutto assassination. "Offering the most definitive public assessment by a U.S. intelligence official, Michael V. Hayden said Bhutto was killed by fighters allied with Mehsud, a tribal leader in northwestern Pakistan, with support from al-Qaeda's terrorist network." U.S. President George W. Bush then placed Mr. Mehsud on "a classified list of militant leaders whom the C.I.A. and American commandos were authorized to capture or kill."

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