Tehrik-i-Taliban Pakistan militants attacked an Army Public School in Peshawar, Pakistan, killing 145 people, mostly schoolchildren.
Tehrik-i-Taliban Pakistan (Urdu: تحریک طالبان پاکستان, lit. 'Taliban Movement in Pakistan', abbr. TTP), alternatively referred to as the Pakistani Taliban, is a Pashtun Islamist armed student group that is an umbrella organization of various student militant groups based along the Afghan–Pakistani border. Most Taliban groups in Pakistan coalesce under the TTP. In December 2007, about 13 groups united under the leadership of Baitullah Mehsud to form the TTP.Among the stated objectives of TTP is resistance against the Pakistani state. The TTP's aim is to overthrow the government of Pakistan by waging a terrorist campaign against the Pakistan armed forces and the state. The TTP depends on the tribal belt along the Afghanistan–Pakistan border, from which it draws its recruits. The TTP receives ideological guidance from and maintains ties with al-Qaeda; it is a different group from the main, Afghan, Taliban, and often opposed to it.
Many of the militants who originally belonged to the TTP were killed as a result of the military operations that the Pakistan Armed Forces conducted in order to destroy the TTP's infrastructure and base of support in Pakistan. However, some of the TTP militants escaped into Afghanistan through the ungoverned areas of the Afghanistan–Pakistan border. In Afghanistan, some of the TTP militants joined Islamic State of Iraq and the Levant – Khorasan Province, while others remained part of the TTP. As of 2019, there are around 3,000 to 4,000 TTP militants in Afghanistan, according to a United States Department of Defense report.In 2020, after years of factionalism and infighting, the TTP under the leadership of Noor Wali Mehsud underwent reorganization and reunification. Between July and November 2020, the Amjad Farouqi group, one faction of the Lashkar-e-Jhangvi, the Musa Shaheed Karwan group, Mehsud factions of the TTP, Mohmand Taliban, Bajaur Taliban, Jamaat-ul-Ahrar, and Hizb-ul-Ahrar merged with TTP. This reorganization has made TTP more deadly and has led to increased attacks.