Piecing together the shadowy lives of the hijackers
American Airlines Flight 11
Crashed into north tower of the World Trade Centre, creating first explosion
Mohamed Atta, aged 33, from Egypt
Atta, from a middle-class family in Giza, on the outskirts of Cairo, carried both United Arab Emirates and Saudi passports.
He studied architecture at Cairo University, moved to Germany and enrolled at Hamburg Technical University in 1993, where he studied engineering and town planning.
He stayed on as a research graduate and visited Syria as part of his studies. In 1995 he disappeared from the college for four years.
He shared a flat with Marwan al-Shehhi in Hamburg, where they held Islamic prayer groups. He was a frequent visitor to America and lived in Daytona Beach, Florida, in the mid-1990s.
In August last year he spent four months at the Huffman Aviation International Flight School, Venice, Florida, training on small planes.
Iraq has denied intelligence reports claiming that he met Iraqi agents in Europe. He re-entered America with al-Shehhi in May on a tourist visa and lived in Florida, where he attended flying schools.
Waleed al-Shehri, age unknown, Saudi Arabia
He and his brother, Wail, are believed to have fought in Afghanistan. It has been reported that they are the sons of a Saudi diplomat who was once posted to Washington.
Waleed learned to fly large aircraft during a four-year degree course in aeronautical science at the Embry-Riddle aeronautical university in Florida. He graduated in 1997.
He was reported to have been in Hollywood, Florida, for a month earlier this year but his father, Ahmed, said that Waleed was alive and well and living in Morocco. He said Wail was treated for mental illness.
Wail al-Shehri, 28, Saudi Arabia.
He sat next to his brother on Flight 11. He, too, was believed to have been a trained pilot, who lived, among other places, in Hollywood, Florida, and Newtown, Massachusetts. In June and July he lived in a motel in Boynton Beach with Satam al-Suqami.
Abdulaziz al-Omari, 29, Saudi Arabia
While studying at the FlightSafety academy, al-Omari moved with his wife and three children to a house in Vero Beach, Florida, close to two suspected terrorists who have been arrested since the attacks.
His wife and children left the house 10 days before the atrocity, saying that they were returning home to Saudi.
Records show that a student with the same name graduated from the University of Colorado, Denver, last year with a degree in engineering.
A man of the same name is also reported to have visited the Philippines in February of this year.
Two safety boxes at a Miami bank were found to be rented under his name.
A man claiming to be al-Omari has told a newspaper that he is alive and well and living in Riyadh. He claimed that his passport was stolen in Colorado five years ago.
Satam al-Suqami, 25, Saudi Arabia
The last address the FBI had for him was in the United Arab Emirates, but he had a Florida driving licence, which bore the address of the Homing Inn, a motel in Boynton Beach, Florida.
It is believed that Wail al-Shehri was at the same motel. Suqami's passport was discovered in the rubble at the site of the World Trade Centre.
United Airlines Flight 175
Crashed into the south tower of the World Trade Centre
Ahmed al-Ghamdi, 21, Saudi Arabia
Al-Ghamdi and al-Suqami have been linked by the FBI to a former cab driver on trial in Jordan over a foiled millennium bomb plot to destroy holy sites and a hotel. The pair had also been linked to an operative from al-Qa'eda.
Al-Ghamdi bought a $1,760 business class ticket for Flight 175 on Aug 29 through the internet, using a post office box at Mail Boxes Etc in Delray Beach for his address.
Two years ago he left the Saudi city of Mecca, where he had been studying engineering, to go to Chechnya.
He is known to have visited Manila more than 13 times and had left the Philippines, where Osama bin Laden is known to have links with terrorist organisations, the day before the attacks.
He stayed in the same Florida apartment as Waleed al-Shehri for seven months in 1997 but also lived in Vienna, in Virginia, and may have had an address at Delray Beach.
Until August last year he appeared to be part of a group of Arab men who often gathered at flats in a complex called the Fountains, near the University of West Florida in Pensacola. He had a Florida identification card.
A man with his name was listed as attending summer classes at the University of Colorado from 1998 to 2000.
Marwan al-Shehhi, 23, United Arab Emirates
He studied German at the University of Bonn in 1997 and 1998 under the name Marwan Lekrab. In 1999 he is believed to have moved to Hamburg, where he shared a flat with Atta. He enrolled at the Technical University but rarely attended classes.
He is known to have studied at Huffman Aviation in Florida with Atta, saying that he wanted a job as a commercial pilot in his home country.
He then studied at the Sim Centre Flight School in Opa-Locka near Miami last December, again with Atta, whom he referred to as "his cousin". They each spent three hours on a flight simulator.
He was identified as one of the men seen drinking in a Florida bar four days before the attacks.
Fayez Ahmed, 28
Ahmed had a pilot's licence and was listed as having trained at the Spartan Aeronautics School in Tulsa, Oklahoma, although the school had no record of him attending.
He visited the Philippines on a Saudi Arabian passport for three days from Oct 17 last year.
Ahmed is thought to have lived in Delray Beach, Florida. He paid $4,500 for his seat and used Mail Boxes Etc in Dalray Beach as his address.
Mohald al-Shehri, 28
Records show that al-Shehri, a qualified pilot, attended the FlightSafety academy in Vero Beach, where he lived.
Within the past month he had used the internet at a Delray Beach library, where he was accompanied by another Middle Eastern man. They had both "looked nervous".
Al-Shehri is believed to have been from the same extended Saudi family as Waleed and Wail al-Shehri.
Hamza al-Ghamdi, 20
Al-Ghamdi, who held a tourist visa and was believed to have been a pilot, lived for several months at Delray Racquet Club, an apartment complex in Delray Beach, Florida, with Ahmed al-Nami and Saeed al-Ghamdi. Hamza al-Ghamdi is believed to have been Ahmed al-Ghamdi's cousin. They used the same box to book their tickets.
American Airlines Flight 77
Crashed into the Pentagon
He was filmed by the CIA in January last year at a meeting in Kuala Lumpur, Malaysia, with a suspect in the attack on the USS Cole in Yemen.
In August, al-Midhar and Nawaq al-Hamzi were put on a list barring entry to America but they had already entered using Saudi documents.
Al-Midhar used an address in Daytona Beach to book a reservation on the American Airlines website, using a frequent flier number that he had established the day before.
He collected his ticket, paying cash, at Baltimore-Washington International Airport on Sept 5.
Al-Midhar flew in a twin-engine Cessna at Sorbi's Flying Club in San Diego in May 2000. Rick Garza, a spokesman, said he was interested in Boeings and flying large planes.
His English skills were too weak to meet federal standards and the classes were ended after half a dozen ground lessons and two flights
At one stage last year he was living with a prominent Muslim leader, Abdussattar Shaikh, in San Diego, claiming to be studying English. He left after only a month, saying he was returning to Saudi Arabia to see his baby daughter. He is said to have been living in New York earlier this year.
Nawaq al-Hamzi, 25, Saudi Arabia
Al-Hamzi was on a US watchlist of suspected terrorists. He lived in Clairemont, San Diego, from September to December last year. With al-Midhar, he flew in a twin-engine Cessna at Sorbi's Flying Club.
He also joined al-Mihdhar living with Abdussattar Shaikh, who said voiced anti-American sentiment.
Al-Hamzi stayed for four months and later called to say he was studying to be a pilot in Arizona. Four years ago, he spent some time in Chechnya.
Recently, he used an address in Delray Beach, Florida, near an apartment complex used by two other hijackers.
He booked his ticket throught the internet travel agency Travelocity using an address at Fort Lee, New Jersey, and bought a second reservation using a Wayne address.
Hani Hanjour, age unknown, Saudi Arabia
He is believed to have lived in Phoenix, Arizona, and then San Diego before moving out at night three weeks before the attacks to Hollywood, Florida.
Records show that he obtained a pilot's licence in April 1999 with a rating to fly commercial jets.
A Federal Aviation Authority record showed that he was granted a six months pilot licence in April 1999 registered to an address in Taife, Saudi Arabia.
Records also show a man with a similiar name held a student's pilots licence while living in Scottsdale, Arizona.
In early August he tried to rent a plane for Freeway Airport, in Washington, claiming 600 flying hours, but performed so poorly on test flights that instructors would not let him fly alone.
However, he is believed to have flown over Washington airspace on three occasions in a Cessna propellor plane shortly before the attacks.
Salem al-Hamzi, 21, Saudi Arabia
He lived in an apartment in Fort Lee, New Jersey, with Nawaq al-Hazmi. He used the address to book his airline ticket through Travelocity. He also lived in San Antonio at one time, and used an address in Jeddah.
Al-Hamzi was listed on an electronic database in the Federal Aviation Administration's airman directory. He left for Chechnya 18 months ago.
Moqed ordered his ticket through the same frequent flier number as al-Midhar and paid for his ticket in cash at Baltimore-Washington International Airport.
United Airlines Flight 93
Crashed in Pennsylvania
Saeed al-Ghamdi, age unknown, Saudi Arabia
It appears that this identity was taken from an innocent Saudi who used to work at Logan Airport in Boston and had his passport stolen. A man claiming to be al-Ghamdi was living at the Delray Racquet Club.
Listed by the FBI as having an address at the FlightSafety academy, students claim not have known him. He also was listed as a licensed pilot in Jeddah and at 405 Lexington Avenue, Manhatten, the address of the United Nations.
In the past year he is believed to have visited the Philippines on at least 15 occasions, entering as a tourist. The last visit ended on Aug 6.
Ziad Jarrahi, 27, Lebanon
A Sunni Muslim, he began an aeronautical engineering course in Germany in 1996 and studied at the University of Applied Science in Hamburg from 1997 until 1999.
He moved to Florida in 1999 and rented homes in Hollywood and Lauderdale-by-Sea. His unwitting father sent him money to start a part-time pilot's course in Miami.
His Turkish-German girlfriend told his parents that he spent five months in Afghanistan. She has not heard from him since the attacks and is now under witness protection.
Ahmed al-Nami, 23, Saudi Arabia
Al-Nami's father said his son interrupted his studies and disappeared 15 months ago. Last December he was living in Delray Beach, Florida, with Saeed al-Ghamdi.
A resident of the Delray Racquet Club complex said she thought they were drug dealers because they were coming and going at all hours, carrying dark bags.
Ahmed al-Haznawi, 20
He entered America on a Saudi passport and recently lived in Lauderdale-by-the-Sea with Ziad Jarrahi. He also used at address at Delray Beach, Florida.