Mr. Sayed was considered close to the Haqqani network, the militant group that has carried out deadly attacks in Afghanistan and has been a cause of diplomatic tensions between the United States and Pakistan. A feared militant commander, he also claimed to have masterminded the 2012 jailbreak in the northwestern town of Bannu that resulted in the escape of nearly 400 inmates, including several high-profile militants.
Pakistani officials have been critical of the American drone strikes on the Pakistani soil, arguing that they are a violation of the country’s sovereignty. But last week’s attack that killed Mr. Sayed did not elicit a strong reaction from Pakistan’s Foreign Office.
Muhammad Khurasani, a Taliban spokesman, said in a statement on Monday that Mr. Sayed had been killed in a Feb. 8 drone strike in Growek region of North Waziristan, another tribal area. American missiles struck a vehicle carrying the militant commander and five of his security guards as they were entering Pakistani territory from the Afghan side, Pakistani intelligence officials said; all of the security guards were also killed in the strike.
Mr. Sayed had gone into hiding in Khost Province of Afghanistan after the Pakistani Army launched an offensive in 2014 against local and foreign militants in North Waziristan.
After the death of the commander Hakimullah Mehsud in a 2013 American drone attack, Mr. Sayed claimed the leadership of the Pakistani Taliban, which consists of several groups. But he then lost out to the current leader, Maulana Fazlullah, who had been responsible for the 2012 attack on Malala Yousafzai, the teenage Pakistani education activist. Differences continued to persist between the two militant commanders.
The man announced by the Taliban as successor to Mr. Sayed is Mufti Noor Wali Mehsud, who also goes by Abu Mansoor Asim. A 588-page book he published online last month, “Inquilab-i-Mehsud,” or “Revolution of the Mehsuds,” chronicles the militant group’s formation and activities, including taking responsibility for the 2007 assassination of former Prime Minister Benazir Bhutto, the first woman to lead a country in the Muslim world.
Mr. Mehsud, 40, is also a Shariah court judge.