Following is a timeline of some of the major attacks carried out or inspired by al Qaeda and its associates:
Feb. 26, 1993 - Six people are killed when a bomb in a van explodes under the twin towers of the World Trade Center in New York. Osama bin Laden is linked to the attack. June 25, 1996 - A bomb in a fuel truck kills 19 American soldiers and wounds nearly 400 people at a U.S. military housing complex in the eastern city of Khobar in Saudi Arabia. The U.S. later brands bin Laden as a prime suspect.
Aug. 7, 1998 - Truck bombs explode at U.S. embassies in Nairobi and Dar es Salaam killing 224, including 12 Americans. Two weeks later, U.S. President Bill Clinton names bin Laden Washington's biggest enemy and launches cruise missiles at sites in Afghanistan and Sudan.
Oct. 12, 2000 - Bombing of U.S. warship Cole in Aden harbour kills 17 sailors and blows hole in navy vessel's hull.
Sept. 11, 2001 - Three hijacked planes crash into major U.S. landmarks, destroying New York's twin World Trade Center towers and plunging into the Pentagon in the worst such attack in modern history. A fourth hijacked plane crashes in Pennsylvania. Nearly 3,000 people are killed in total.
April 11, 2002 - A truck explodes near El Ghriba synagogue on the southern Tunisian island of Djerba, killing 14 Germans, five Tunisians and a Frenchman. Al Qaeda claims responsibility.
Oct. 12, 2002 - Bombs explode in Kuta Beach nightclub district of Bali in Indonesia, killing 202 people. Members of banned Islamic group Jemaah Islamiyah, linked to al Qaeda, admit responsibility.
Nov 28, 2002 - Three suicide car bombers blow up a hotel popular with Israelis in the Kenyan resort of Mombasa, killing 15 people. On the same day, two missiles narrowly miss an Israeli Arkia Boeing 757 carrying 261 passengers on take-off from Mombasa airport. Al Qaeda says it was responsible.
May 12, 2003 - At least 35 people, including nine Americans, are killed by al Qaeda bombers in Riyadh, Saudi Arabia.
May 16, 2003 - Coordinated blasts in Casablanca, Morocco kill 45 people, including 13 bombers, and wound about 60.
Aug. 19, 2003 - A suicide truck bomb wrecks the Canal Hotel, which served as U.N. headquarters in Baghdad, killing 22 people, including U.N. envoy Sergio Vieira de Mello. In the following months and years, al Qaeda carries out numerous attacks in Iraq under its local leader Abu Musab al-Zarqawi, including bombings, kidnappings and the beheading of hostages.
Nov. 9, 2003 - Al Qaeda suicide bombers kill up to 30 people in a Riyadh residential compound.
July 7, 2005 - Four suicide bombers kill 52 people in attacks on three London underground trains and a bus. In September, Al Qaeda's no. 2 Ayman al-Zawahri says al Qaeda carried out the bombings to strike at "British arrogance".
Nov. 9, 2005 - Bombers attack three hotels in Jordan's capital Amman. Fifty-seven people and three bombers are killed. Iraq's al Qaeda group claims responsibility.
April 11, 2007 - Suicide bombs kill 33 people in central Algiers, the first big bomb attacks in the centre of the Algerian capital in more than a decade. They are later claimed by the al Qaeda Organisation in the Islamic Maghreb (AQIM).
Dec. 11, 2007 - Two blasts kill at least 41 people, including 17 U.N. staff, at U.N. offices in Algiers. Al Qaeda claim responsibility.
Dec. 25, 2009 - A Nigerian man, Umar Farouk Abdulmutallab, is accused of attempting to bomb a U.S.-bound passenger plane. The Yemen-based al Qaeda in the Arabian Peninsula (AQAP) claims responsibility.
Jan. 25, 2010 - Three suicide bombs rock hotels in the Iraqi capital, Baghdad, killing at least 36. Al Qaeda-linked insurgents claim responsibility.
July 2010 - French tourist Michel Germaneau killed by AQIM, three months after it kidnapped him in Niger.
Oct. 31, 2010 - Gunmen seize hostages during Sunday mass at a church in Baghdad. Around 52 hostages and police are killed. Al Qaeda's Iraqi affiliate claims responsibility for the attack on "the dirty den of idolatry".
Nov. 5, 2010 - AQAP claims responsibility for a foiled plot to send explosive parcels to the United States. Two parcel bombs were intercepted on cargo planes in Britain and Dubai. Jan 2011 - France says AQIM was almost certainly behind the abduction of two Frenchmen killed in Niger.
April 28, 2011 - A bomb kills 15 people including 10 foreigners in Marrakesh, Morocco, in an attack that bore the hallmark of Islamist militants. The previous week, men claiming to be Moroccan members of AQIM appeared on the Internet threatening to attack Moroccan interests.
Sources; Reuters/Jane's World Insurgency and Terrorism: