A timeline of the worst assaults and bombing attributed to the Taliban and other militant groups.
Gunmen attacked a university in Charsadda on Wednesday and police said at least 21 people were killed. A faction of the Pakistani Taliban, whose insurgency has killed thousands since it erupted in 2007, claimed responsibility.
Here is a list of major attacks by them and others since 2007:
Oct. 18: Bomb attacks targeting former prime minister Benazir Bhutto kill 139 people in Karachi as she returns to Pakistan for the first time in eight years. She was later killed in another gun and suicide attack on Dec. 27.
Aug. 21: Twin suicide attacks kill 64 people outside Pakistan’s main arms factory in Wah near Islamabad.
Sept. 20: Sixty people are killed when a suicide truck bomb brings down part of the five-star Marriott hotel in Islamabad.
Oct. 28: A car bomb destroys a market in Peshawar, killing 125 people.
Jan. 1: A suicide car bomb kills 101 people at a village volleyball game in Bannu.
March 12: Twin suicide attacks on the military in Lahore kill 57.
May 28: Gun and suicide attackers storm mosques belonging to the Ahmadi community in Lahore, killing 82 people.
July 9: A suicide bomber blows himself up in a busy market in Mohmand, killing 105 people.
Sept. 3: A suicide attack kills 59 at a Shia rally in Quetta.
Nov. 5: A suicide bomber kills 68 people during Friday prayers in Darra Adam Khel.
April 3: Fifty die after two suicide bombers attack a Sufi shrine in Dera Ghazi Khan.
May 13: Two suicide bombers kill at least 98 people outside a police cadet training center in Charsadda.
Aug. 19: A suicide bomber hits a mosque during Friday prayers in Khyber Agency, killing at least 43.
Jan. 11: Thirty-five die when a remote-controlled bomb detonates in a market in the northwestern tribal areas.
Aug. 16: Gunmen drag 20 Shia Muslims off a bus and shoot them in Mansehra.
Jan. 10: A double suicide attack on a snooker club kills 92 in a Shia Hazara neighborhood of Quetta.
Feb. 16: A bomb at a market at Hazara Town, a Shia Hazara neighborhood in Quetta, kills 89.
March 3: A car bomb explodes in a Shia Muslim neighborhood in Karachi, killing 45.
July 27: Twin explosions at a busy marketplace in northwest Pakistan kill 41.
Aug. 9: A suicide bomber targets the funeral of a senior police officer in Quetta, killing 38.
Sept. 22: Eighty-two people die when two suicide bombers attack a church in Peshawar after a Sunday service.
Sept. 29: A car bomb in a busy market area in Peshawar kills 42.
Jan. 19: A bomb rips through a military convoy in Bannu, killing 20 soldiers.
Jan. 21: A bomb on a bus kills 24 Shia pilgrims in Balochistan.
June 10: Ten Taliban militants lay siege to Karachi airport, killing 27 people.
Nov. 2: Fifty-five people are killed by a suicide bomber at the daily closing ceremony at the main Pakistan-India border crossing.
Dec. 16: Taliban insurgents storm an Army-run school in Peshawar, killing at least 154 people including 135 children.
Jan. 30: 62 people are killed as a suicide bomber hits a Shia mosque in the Shikarpur district.
Feb. 13: Militants attack a Shia mosque in Peshawar, killing 22.
May 13: Forty-three Shia Muslims are killed when gunmen open fire on their bus in Karachi.
Sept. 18: The Pakistani Taliban attack an air force base near Peshawar and kill at least 29 people, most of them servicemen.
Oct. 23: A suspected suicide blast, which targeted Shia Muslims in Jacobabad, kills 24.
Dec. 13: A bomb rips through a crowded bazaar in a mainly Shia area of the tribal areas, killing at least 23.
Dec. 29: A Taliban suicide bomber on a motorcycle kills 26 in Mardan.
Jan. 20: Taliban gunmen attack a university in Charsadda, killing at least 21.