Fourteen key US terror suspects previously held in secret CIA prisons have been sent to Guantanamo Bay, Cuba.
The men, who are being kept in a high security block at the US naval base, are expected to face trial, President George W Bush has said.
The following profiles and what is known of the allegations against the suspects are compiled from BBC reports, news agency copy and information released by the Pentagon and US intelligence officials.
KHALID SHEIKH MOHAMMED
Khalid Sheikh Mohammed - described by US intelligence as "one of history's most infamous terrorists" - has admitted being responsible "from A to Z" for the 11 September 2001 attacks on the United States, according to the Pentagon.
Khalid Sheikh Mohammed: alleged 9/11 lynchpin
He also confessed to a role in 30 plots other than 9/11 including planned attacks on Big Ben and Heathrow airport in London and the beheading of US reporter Daniel Pearl in Pakistan in 2002, according to a transcript of his hearing at Guantanamo Bay.
He was believed to be the Number 3 al-Qaeda leader before his capture in a safe house in Pakistan in March 2003. He was held in US custody at an undisclosed location from then until his transfer to Guantanamo Bay in 2006.
Born in Kuwait of Pakistani extraction, Khalid Sheikh Mohammed claims to have joined the Muslim Brotherhood at the age of 16.
After graduating from college in the US, he went to Afghanistan to participate in the anti-Soviet jihad. It was there that he is believed first to have met Osama Bin Laden.
He went to the Philippines and was implicated in the plot to blow up US airliners over the Pacific in 1995, known as Operation Bojinka.
He features prominently in the US 9/11 Commission Report on how the 11 September 2001 attacks were carried out. His testimony was also used by defence lawyers for Zacarias Moussaoui, jailed for life in 2006 for his role in the plot.
Khalid Sheikh Mohammed helped build close operational ties between al-Qaeda and the shadowy militant group Jemaah Islamiah (JI) in south-east Asia, according to US intelligence.
By late 2001 he had become external operations chief for al-Qaeda and was involved in plots targeting Britain and the US, the Pentagon says.
Pakistani President Pervez Musharraf has alleged that he also helped lay the groundwork for the 7 July 2005 bombings in London.
Abu Zubaydah is thought to have been the link between Osama Bin Laden and many al-Qaeda cells before his capture in Pakistan in March 2002.
Abu Zubaydah was said to be a key al-Qaeda travel facilitator
The Americans describe him as "one of al-Qaeda's senior travel facilitators" and credit him with helping to smuggle the former al-Qaeda in Iraq leader Abu Musab al-Zarqawi and some 70 fighters out of Afghanistan into Iran.
At the time of his capture, Abu Zubaydah was trying to organise a terror attack in Israel, US intelligence officers say.
Believed to have been born to Palestinian parents in Saudi Arabia, he is also known as Zayn al-Abidin Mohammed Husain and Abd al-Hadi al-Wahab but has used dozens of other aliases.
He has strong connections with Jordanian and Palestinian groups and was sentenced to death in his absence by a Jordanian court for his role in a thwarted plot to bomb hotels there during millennium celebrations.
US intelligence officials say that although he is not believed to be directly linked to the 11 September attacks, money he procured from donors may have helped fund that plot and others.
Zubaydah is also thought to have helped run a number of al-Qaeda camps in Afghanistan, at which some of the 9/11 hijackers and other terror suspects trained.
According to a Senate report, Zubaydah has told US interrogators that while he believed some al-Qaeda members had good personal relationships with Iraqi government officials he was unaware of any real relationship between Baghdad and the network.
In his combatant status review at Guantanamo Bay, the US cited evidence describing Ramzi Binalshibh as the co-ordinator of the 9/11 attacks.
Ramzi Binalshibh is one of the alleged masterminds of 9/11
He is said to have become a key member of the al-Qaeda cell in Hamburg, Germany, after seeking asylum there in the late 1990s and becoming a student.
According to US officials, he met Mohammed Atta, the leader of the Hamburg cell, and two other hijackers, Marwan al-Shehhi and Ziad Jarrah, in 1997. Two years later, the four travelled to Afghanistan where they met Bin Laden.
Binalshibh was intended to be one of the hijackers but was unable to get a US visa, intelligence officials say.
Instead, he reportedly assisted the 11 September attacks by relaying orders from al-Qaeda's leadership in Afghanistan and Pakistan to operatives in the US and Germany, as well as organising travel and money transfers.
US intelligence says he left Germany a week before the attacks and made his way to Afghanistan and then to Pakistan, where he worked with Sheikh Mohammed on plots against Western targets, including plans to crash aircraft into Heathrow airport in the UK.
He was interviewed by an al-Jazeera reporter in 2002, during which he showed souvenirs of the 9/11 planning, including a flight instruction book signed by lead hijacker Mohammed Atta.
He was captured in Pakistan in September 2002.
The US described him at his combatant status review as "uncooperative and unresponsive", vowing to have nothing to do with the process.
HAMBALI (RIDUAN ISAMUDDIN)
Indonesia-born Hambali is believed to have been the operations chief for the shadowy militant group Jemaah Islamiah (JI), and has been named as a key suspect in a string of bombings across the region.
Hambali is suspected of playing a leading role in the Bali bombing
According to the US, he was the main liaison between JI and al-Qaeda from 2000 until his capture in 2003.
Intelligence officials accuse him of planning the first Bali bombing in 2002, in which 202 people died, and raising funds from al-Qaeda for the 2003 attack on the Marriott hotel in Jakarta, which killed 12.
They say he was also involved in the attempted assassination of the Philippine Ambassador to Indonesia in August 2000 and in the bombing of churches in nine Indonesian cities on Christmas Eve that year, in which 18 people died.
Born in West Java in 1964, he is said to be the oldest of 11 children and to have been a devout Muslim youth.
As a teenager Hambali joined a network of local groups known broadly as Jemaah Islamiah.
He became involved in radical Islam as a reaction against the religious repression of the Suharto regime throughout the 1970s and 1980s. In 1985, when Hambali was aged 19, he sought exile in Malaysia, along with radical Muslim cleric Abu Bakar Ba'asyir and other followers.
Ba'asyir was last year convicted of conspiracy over the 2002 Bali bombings.
From Malaysia, Hambali travelled to Afghanistan in 1988 to fight as a Mujahideen guerrilla against Soviet occupation.
He returned to Malaysia in 1990, where he is believed to have travelled the country recruiting young Muslims to join a jihad (holy war) with the eventual aim of setting up a pan-Asian Islamic state.
Philippine prosecutors have charged Hambali in absentia with involvement in a plot to smuggle explosives from the Philippines to Singapore in 2000, for an attack on US and Israeli targets, which was foiled.
MUSTAFA AHMAD AL-HAWSAWI
A Saudi said by US intelligence officials to be one of two key financial people used by Khalid Sheikh Mohammed to arrange the funding for the 11 September hijackings.
He is suspected of meeting many senior al-Qaeda figures, including Bin Laden, soon after the attacks. Financial links have been found between Hawsawi, other terror suspects and some of the hijackers, US intelligence says., and he helped arrange travel for some of them.
Testimony from Hawsawi was used in the trial of Zacarias Moussaoui, saying he had seen him in an al-Qaeda guesthouse in early 2001 but was never involved with him.
He was captured in Pakistan in 2003.
ABU FARAJ AL-LIBBI
Abu Faraj al-Libbi
Abu Faraj al-Libbi was arrested in Pakistan along with five other al-Qaeda suspects in May 2005, after a gun battle in Waziristan, North-West Frontier Province.
Libbi is wanted over assassination attempts on President Musharraf
A Libyan, he is said to have taken over as third in command of al-Qaeda when his mentor, Khalid Sheikh Mohammed, was captured in 2003.
The Americans say he carried messages between Bin Laden and senior al-Qaeda members. He is also accused of trying to recruit new operatives.
He is described as the mastermind of two failed attempts to assassinate Pakistani President Pervez Musharraf.
He is thought to have used Pakistan as his base, and from there was reportedly in contact with militants in the UK. Following his arrest, he was handed over by Pakistan to US custody.
He has refused to take part in the combatant status review at Guantanamo Bay, preferring to wait for formal legal proceedings.
He described the tribunal as "a good initial step towards justice and righteousness", but complained that he had had no access to a lawyer.
MOHAMMED NAZIR BIN LEP
A Malaysian better known as Lillie, he is said by the US to be a key aide to Hambali.
He was allegedly involved in transferring al-Qaeda funds for the 2003 Marriott Hotel bombing in Jakarta, in which 12 people died, and is also accused of involvement in other plots against targets in South-east Asia.
According to US intelligence, he was intended to be a suicide attacker in a planned al-Qaeda operation in Los Angeles.
ALI ABD AL-AZIZ ALI
Also known as Ammar al-Baluchi, he is accused of serving as a key lieutenant to Khalid Sheikh Mohammed - his uncle - during the 11 September operation.
Born in Balochistan and raised in Kuwait, his chief mentor was his cousin, Ramzi Yousef, jailed in the US for masterminding the 1993 bombing of the World Trade Center.
US intelligence officials say he delivered funds to the 11 September hijackers and later helped Sheikh Mohammed communicate with "shoe bomber" Richard Reid and other plotters, including Majid Khan.
Following his uncle's arrest, he is said to have assumed responsibility for planning hijacking attacks from Heathrow airport and bombings against Western targets in Karachi in 2003.
He was within days of completing preparations for the Karachi plot when captured, the US says.
WALID BIN ATTASH
Yemeni national Walid bin Attash has admitted masterminding the bombing of the American destroyer, USS Cole, in Yemen in 2000, which killed 17 sailors, according to the Pentagon.
Mr Attash also said he helped plan the 1998 bomb attacks on the US embassies in Kenya and Tanzania that killed 213 people, according to a transcript of his hearing at Guantanamo Bay.
Mr Attash, also known as Tawfiq bin Attash and Khallad, was a key al-Qaeda operative from 1998 until his capture in 2003, according to the US.
He is also accused of involvement in the 11 September 2001 attacks and met two of the hijackers, Nawaf al-Hamzi and Khalid al-Midhar, to help them check out US flights in Asia.
He was allegedly picked as one of the hijackers himself but was prevented from taking part when he was briefly arrested in Yemen earlier that year. He is said to have served as Bin Laden's bodyguard.
US intelligence officials say he was planning an attack on the US consulate in Karachi with fellow suspect Ali Abd al-Aziz Ali when he was captured in a raid in the city. They believe he was also involved in a plot against Heathrow airport.
Pakistani-born Majid Khan moved to the US in the late 1990s, where he went to high school in Baltimore.
Majid Khan is accused of planning to blow up US petrol stations
According to the US, on his return to Pakistan family members introduced him to senior al-Qaeda figure Khalid Sheikh Mohammed, who groomed him for a possible attack to blow up petrol stations within the US.
He is said to have been selected for his familiarity with the US, his excellent English and experience of working at an American petrol station.
The alleged plot was at the centre of a 2005 trial of a young Pakistani man accused of trying to help Khan obtain fake travel documents to enter the US.
Khan is also accused of having links to fellow suspect Ali Abd al-Aziz Ali and of passing money to Jemaah Islamiah (JI) operative Mohd Farik Bin Amin, better known as Zubair.
Testifying to a military tribunal at Guantanamo on 15 April 2007, Khan denied being an enemy combatant, an extremist and said he had no links with al-Qaeda.
He also said he had been "mentally tortured" by the US authorities and that it had led him to try to commit suicide by chewing on an artery.
ABD AL-RAHIM AL-NASHIRI
A Yemeni court in September 2004 sentenced Abd al-Rahim al-Nashiri to death over the bomb attack on the USS Cole, which killed 17 sailors in 2000.
The Saudi-born militant was tried in absentia, having been in US custody since his arrest in the United Arab Emirates (UAE) in October 2002.
Nashiri confessed to involvement in the USS Cole attack, but in a transcript of the military tribunal held after he was transferred to Guantanamo Bay, he said his confessions were obtained under torture.
According to US intelligence, he was the leader of the al-Qaeda network's operations in the Gulf and the mastermind of the bombing of the USS Cole off the coast of Yemen.
He is also believed to have been involved in plots against Western targets in the UAE, Saudi Arabia, the Strait of Gibraltar, Morocco and Qatar.
He allegedly fought with the Taleban in Afghanistan and was involved in earlier Chechen and Tajik insurgencies.
AHMED KHALFAN GHAILANI
The Tanzanian has been charged with war crimes by the Pentagon in relation to the attack on the US embassy in Dar es Salaam in 1998. He could face the death penalty if convicted.
He admitted delivering explosives used to blow up the embassy in 1998, according to transcripts of a hearing released by the Pentagon in March 2007.
However, Mr Ghailani said he did not know about the attack beforehand and apologised to the US and the victims' families for his role, the Pentagon says.
According to the US transcript, Mr Ghailani admitted visiting an al-Qaeda training camp in Afghanistan after the bombings. But he denied being a member of al-Qaeda.
He allegedly went on to become one of al-Qaeda's top document forgers after 11 September 2001 and served as a bodyguard for Osama Bin Laden.
GOULED HASSAN DOURAD
Originally from Somali, Gouled Hassan Dourad is accused of heading a Mogadishu-based network which supported al-Qaeda members in the country.
According to the Americans, he was privy to several plots, including one to attack a US military base in Djibouti and another to shoot down an Ethiopian airliner.
MOHD FARIK BIN AMIN
Better known as Zubair, Mohd Farik Bin Amin is said to have been a member of al-Qaeda and Jemaah Islamiah (JI) serving directly under Hambali.
The Malaysian allegedly assisted major JI operations and was picked as a possible suicide attacker for a planned al-Qaeda operation in Los Angeles, US intelligence officials say.