PESHAWAR - Chief of the banned Tehreek-e-Taliban Pakistan’s splinter group Jamaat-ul-Ahrar (JuA) and a mastermind of Army Public School Peshawar massacre has been killed in a US drone attack in Afghanistan.

Earlier on Tuesday, it was reported that JuA chief Umar Khalid Khorasani had sustained critical injuries in the US drone strike carried out near Pak-Afghan border in Paktia province of Afghanistan. Due to his injuries, he was moved to an undisclosed location by his aides.

In three back-to-back US drone strikes, at least 31 people had been killed near the Pak-Afghan border in Afghanistan on Monday and Tuesday.

On Wednesday, the TTP confirmed the death of Umar Khalid Khorasani. Also known as Abdul Wali and Umar Naray, Khorasani was said to be the mastermind of the attack on Peshawar’s Army Public School, one of the deadliest terrorist attacks in the country in which over 140 people, mostly students and staff members of the school, had been killed in December 2014.

Moreover, he had also claimed the Bacha Khan University attack killing more than 22 people including students and a PhD teacher of Chemistry subject in February 2016.

Stated to be in his 40s, Khorasani was educated in Islamabad and later at a seminary. He worked as a labourer in Karachi before joining the TTP in late 2007. His nickname was “Nary,” a word in the Pashto language meaning ‘slim’, and he was the father of two daughters and a son.

Usman Mansoor Hafizullah will replace Umar Khalid as the faction’s new chief in Darra Adam Khel and Peshawar, TTP Spokesperson Muhammad Khorasani said in an email sent to journalists.

Earlier, Umar Khrasani was reported to have been killed in July last year. However, his death was not confirmed by TTP’s splinter group. This is the first time his death has been confirmed by the militant outfit.

In July last, Pakistan welcomed the United Nations Security Council’s decision to include JuA in the list of entities subject to travel bans, arms embargos and freezing of assets. The JuA is based in Nangarhar province of Afghanistan and has been involved in a series of terrorist attacks inside Pakistan.

Pakistan had proscribed JuA in 2016. Since 2014, when the Jamaat-ul-Ahrar first surfaced, it proved itself to be a lethal terrorist group, perpetrating some of the most brutal attacks in Pakistan.

Hailing from Mohmand Agency, Umer Khalid Khorasai was one of the powerful commanders of the TTP. He has also been chief of the TTP for Mohmand Agency when Baitullah Mehsud was its central ameer. He rose to sight in 2007, after laying siege to the shrine in Mohmand Agency’s village Ghaziabad and renamed it as Lal Masjid.

Agencies add: Grieving parents welcomed the news of Umar’s death.

“The entire world is happy over the killing of the mastermind” behind the Peshawar school assault, Tufail Khan Khattak, whose son was killed in the attack, told AFP.

The TTP did not say in its message that when or where Khalifa Umar had been killed, and there was no immediate comment from the Pakistani military or government.

The APS attack - swiftly termed Pakistan’s 9/11 - shocked a country already grimly accustomed to atrocities, and spurred the military to intensify an operation in the tribal areas, where militants had previously operated with impunity.

Pakistan has seen a dramatic improvement in security in the years since, though militant groups such as the TTP retain the ability to carry out spectacular attacks across the country.

That included another attack by the TGG, designated a terrorist group by the US.

After both attacks, Umar issued videos vowing to target schools across Pakistan, calling them “nurseries” for people who challenge Allah’s law.