Following is a timeline of major attacks in Pakistan since July 2007, after gunmen stormed a police academy outside the city of Lahore in an assault officials say has killed at least 20 people.
July 15: Suicide attacks kill at least 47 people in northwest Pakistan, including 26 at a police recruitment centre.
July 19: Three suicide attacks kill more than 50 people. The deadliest targets Chinese workers in southwestern Pakistan, but kills only locals.
October 18: Bomb attacks targeting two-time former premier Benazir Bhutto kill at least 139 people in Karachi, just hours after she returns to Pakistan for the first time in eight years. She survives unhurt.
December 21: At least 50 are killed in an attack on a mosque in the northwest of the country.
December 27: A gun and suicide bomb attack kills Bhutto and nearly two dozen of her supporters as she leaves a campaign rally in Rawalpindi. The interior ministry later says another 58 people died in a wave of unrest triggered by the former premier's assassination.
February 16: Suicide car bomber strikes a rally by Bhutto's party in the northwestern tribal town of Parachinar, killing 37.
February 29: A suicide bomber kills 44 people in Mingora, the main town in the troubled Swat valley, during the funeral of three policemen killed by a roadside bomb earlier in the day.
March 2: Suicide bomber kills 43 at a meeting of anti-militant tribal elders in the northwestern district of Darra Adam Khel.
March 10: Suicide attackers detonate two huge truck bombs in Lahore, killing 26 people and partly demolishing the Federal Investigation Agency building in the city.
July 6: Suicide bomber kills 15 people in an attack on police in Islamabad during a rally to mark the anniversary of an army raid on the radical Red Mosque.
August 21: Twin suicide attacks kill at least 57 people outside Pakistan's main arms factory in Wah, near Islamabad.
September 6: Suicide bomber kills 33 people at a security checkpoint near Peshawar, the capital of North West Frontier Province.
September 20: At least 60 people are killed when a suicide attacker rammed a massive truck bomb into the gates of the five-star Marriott hotel in Islamabad
October 10: A suicide bomber blows himself up at a meeting of anti-Taliban tribal leaders in a Pakistani region of Orakzai district, killing at least 40 people.
December 5: At least 27 people are killed and dozens injured when two bomb blasts struck crowded markets in northwest Pakistan.
December 28: At least 41 people are killed in a bomb blast at a polling station in the town of Buner on the edge of the Swat valley in northwest Pakistan.
February 5: 35 people are killed when a suspected suicide bombing hits a crowd of Shiite worshippers outside a Pakistani mosque in Dera Ghazi Khan.
February 20: Thirty people are killed in a suicide bombing at a funeral procession for an assassinated local Shiite Muslim leader in Dera Ismail Khan in northwest Pakistan.
March 3: Gunmen mount a brazen, coordinated attack on Sri Lanka's touring cricket team in Lahore, killing eight Pakistanis as well as wounding seven players and a coach.
March 27: A suicide bomber attacks a packed mosque in the northwestern town of Jamrud at prayer time, killing around 50 people and wounding dozens more.
March 30: Gunmen storm a police training compound at Manawan, near Lahore, unleashing a fierce battle with security forces that kills at least 20 people.