The Tehreek-i-Taliban Pakistan (TTP) on Wednesday named a successor for militant commander Umar Mansoor, the mastermind of the Army Public School attack, along with a formal confirmation that he was dead.

Usman Mansoor Hafizullah will replace Umar Mansoor as the faction's commander in Darra Adam Khel and Peshawar, TTP Spokesperson Muhammad Khorasani said in an email sent to journalists on Wednesday.

Umar Mansoor, who had also claimed responsibility for the deadly attack on Bacha Khan University in 2016, was said to be the mastermind of 2014's massacre at the Army Public School in Peshawar which left at least 144 people, mostly children, dead.

Two senior security officials had told Dawn that Umar Mansoor, alias Khalifa Mansour, alias Umar Naray, had been killed, along with another militant leader, Qari Saifullah, in a US drone attack in the Bandar area of Afghanistan’s Nangarhar province in July 2016.

One of the officials had said they had credible reports of Mansoor having been killed with Saifullah, who was in charge of suicide bombers. “What we have is pretty credible,” he had said.

Later, then Commander of the Resolute Support Mission, Gen John Nicholson, had called retired Gen Raheel Sharif and confirmed the death of “terrorist Umar Naray alias Khalifa Umar alias Khalid Khurasani” in Afghanistan.

Correction: An earlier version of this story incorrectly stated that Abdul Wali aka Umar Khalid Khorasani , the chief of the outlawed Jamaat-ul-Ahrar, had been killed. The individual is unrelated despite the similarity in the alias (Khalid Khorasani). The error is regretted.