Abu Hamza al-Masri and four other men suspected for their involvement in terrorist activities have been extradited to the US after they lost their appeal in a London court.
Al-Masri and fellow suspects Babar Ahmad, Talha Ahsan, Adel Abdul Bary and Khaled Al Fawaaz, left from the Mildenhall air force base on Friday, in eastern England, which is used by the US military.
The two jets provided by the US authorities took off shortly before midnight (23:00GMT), Scotland Yard police headquarters said.
The five suspects are expected to appear in US courts on Saturday after their arrival where judges will set dates for their trials.
The defendents will face eleven charges including planning to establish a "terrorist" training camp for islamic jihadists in the US state of Oregon and conspiracy to take hostages in Yemen in 1998.
Al-Masri will face a court in New York along with Khalid al Fawaz and Adel Abdul Bary, but Babar Ahmed and Talhar Ahsan are expected to face hearings in Connecticut, where the courts have jurisdiction over their case.
Earlier, the High Court in London dismissed al-Masri's appeal against extradition to the US on terror charges, along with the four others. The decision marks the end of a long legal battle over their fate.
Judges Duncan Ouseley and John Thomas handed down the judgment on Friday in the case of al-Masri along with four other defendents who are accused of terrorist activities.
|Babar Ahmed has been held in a UK prison without trial for eight years on suspicion of raising funds for terrorism
Their appeal came after the European Court of Human Rights backed successive UK courts in ruling for extradition.
The Home Office said it wanted to deport them "as quickly as possible".
Judges Thomas and Ousley said in their ruling there was an "overwhelming public interest in the functioning of the extradition system" and that there was "no appeal from our decision".
Al Jazeera's Peter Sharp reporting from London, says: "Abu Hamza has been in jail since 2004, he has already been charged by the British courts, now the Americans have charges against him."
Ahmad, a computer expert from South London, has been held in a UK prison without trial for eight years after being accused of raising funds for terrorism with his co-accused, Ahsan, through a website.
Fahad Ansari, a human-rights lawyer with Free Babar Ahmad Campaign, told Al Jazeera he is disappointed with the High Court ruling.
"In the past year, two parliamentary committees, numerous senior politicians from all parties, the mayor of London, and 150,000 ordinary members of the British public have called for Babar Ahmad to be tried in the UK," he said.
"In the past year, two parliamentary committees, numerous senior politicians from all parties, the mayor of London, and 150,000 ordinary members of the British public have called for Babar Ahmad to be tried in the UK"
- Fahad Ansari, Free Babar Ahmed Campaign
"This decision flies in the face of that and questions need to be asked as to how and why members of the judiciary have ignored both the public interest in Babar Ahmad being prosecuted in the UK."
The suspects applied to the High Court for a last-minute halt, with al-Masri's lawyers saying his deteriorating health means it would be "oppressive" to send him to a US prison.
Lawyers for al-Masri, said he suffered from depression, chronic sleep deprivation, diabetes and other ailments and was in need of medical tests.
Bary and al-Fawwaz were indicted with others, including Osama bin Laden, for their alleged roles in the bombings of two US embassies in east Africa in 1998. Al-Fawwaz faces more than 269 counts of murder.
The various extradition bids have dragged on for as long as 14 years amid wrangles over whether the defendants' human rights would be respected by US authorities.