TIMELINE: EVENTS SURROUNDING 9/11 ATTACKS

This is a timeline of key events leading up to and since the September 11 attacks on the United States.

February 26 1993 - Islamic terrorists set off a massive truck bomb in a basement car park under the World Trade Centre in New York, killing six people and injuring 1,000 others.

August 7 1998 - Al Qaida, a terror group founded by wealthy Saudi fundamentalist Osama bin Laden, bombs the US embassies in Kenya and Tanzania, killing 224 people.

September 11 2001 - The tranquility of a bright sunny morning in Manhattan is shattered when a passenger jet hijacked by al Qaida terrorists smashes into the north tower of the World Trade Centre at 8.46am local time, followed 17 minutes later by a second airliner crashing into the south tower.

A third aircraft strikes the Pentagon in Washington DC at 9.37am and a fourth crashes into the ground near Pittsburgh, Pennsylvania, at 10.03am.

Both towers of the World Trade Centre collapse, crushing those still inside, including firefighters and other emergency workers. The attacks claim nearly 3,000 innocent lives, including 67 Britons.

October 7 2001 - The war in Afghanistan begins with American and British forces launching attacks on al Qaida training camps and the Taliban regime in Kabul.

December 22 2001 - London-born al Qaida sympathiser Richard Reid is overpowered by passengers as he tries to detonate explosives in his shoes in a failed attempt to bring down an airliner flying from Paris to Miami.

January 11 2002 - America begins moving terror suspects arrested in Afghanistan, among them Britons, to a military detention centre at Guantanamo Bay naval base on Cuba.

October 12 2002 - An al Qaida-linked terror group sets off two bombs in a bar and nightclub on the Indonesian island of Bali, killing 202 people, including 28 Britons.

March 20 2003 - Nearly 50,000 UK troops take part in the US-led invasion of Iraq, which quickly results in the overthrow of Saddam Hussein but also leaves the country wracked by bloody sectarian violence.

March 11 2004 - Islamic terrorists set off a series of bombs on commuter trains in Madrid, killing 191 people.

July 7 2005 - Suicide bombers carry out co-ordinated attacks in London on three Tube trains and a double-decker bus, killing 52 innocent people and wounding more than 700.

August 9 2006 - British police foil a London-based terror cell planning to blow up passenger jets flying from the UK to North America in mid-air using homemade liquid bombs. Six men were convicted over the plot after a series of trials.

June 29 2007 - Two car bombs are left in central London early in the morning but fail to go off.

The next day the terrorists behind the botched attack drive a Jeep Cherokee packed with petrol, gas canisters and nails into the main terminal building at Glasgow Airport. One of the extremists dies but they do not claim any victims.

April 30 2009 - The UK ends its combat operations in Iraq with a sombre remembrance service for the 179 British personnel killed in the conflict.

December 25 2009 - University College London graduate Umar Farouk Abdulmutallab launches a failed attempt to blow up a flight to Detroit by setting off explosives hidden in his underwear.

October 29 2010 - A sophisticated bomb disguised as a printer toner cartridge is found at East Midlands airport on a UPS cargo flight from Yemen bound for Chicago in the US.

December 1 2010 - US president Barack Obama announces he is sending an extra 30,000 troops to Afghanistan in an attempt to reverse the allies' fortunes in the flagging war.

May 1 2011 - Bin Laden is killed by US special forces in Abbottabad, Pakistan.