The Tehreek-i-Taliban Pakistan (TTP) on Wednesday confirmed that militant commander Umar Mansoor, the mastermind of the Army Public School attack , had been killed .

“We confirm the death of Khalifa Umar Mansoor, and Khalifa Usman Mansoor Hafizullah will be replaced as the faction’s commander in Darra Adam Khel and Peshawar, the TTP said in a statement sent to journalists via email on Wednesday.

According to sources, he was wounded in a drone strike carried out in Paktia province of Afghanistan on Tuesday, and moved to an undisclosed location by his accomplices. He succumbed to his injuries today.

Umar Mansoor 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.