Extremist Islamic cleric Abu Hamza al-Masri and four other men departed England on Friday night destined for the United States, hours after the High Court in London ended a years-long legal battle by ruling the men could be extradited "immediately."

Two planes left the British Air Force base Mildenhall with al-Masri, Khaled al-Fawwaz, Adel Abdul Bary, Babar Ahmad and Talha Ahsan so they could face trial in the United States, Home Secretary Theresa May said in a statement.

"We have worked tirelessly -- alongside the U.S. authorities, the police and the prison service -- to put plans in place so that tonight these men could be handed over within hours of the court's decision," May said. "It is right that these men, who are all accused of very serious offenses, will finally face justice."

Earlier Friday, Judge John Thomas ruled that the British court's decision authorizing the extradition of the men could not be appealed and said it "may proceed immediately."

The charges against al-Masri include conspiracy in connection with a 1998 kidnapping of 16 Westerners in Yemen, and conspiring with others to establish an Islamic jihad training camp in rural Oregon in 1999. He could be sentenced to life in prison if convicted.

The UK Home Office earlier welcomed the High Court decision, and May said in her statement "that these men ... used every available opportunity to frustrate and delay the extradition process over many years."

The U.S. Embassy in London said it was "pleased" by the court's ruling.

"All of these defendants will be guaranteed the same rights provided to American citizens charged with crimes in the U.S. They will be afforded a full opportunity to challenge the evidence against them in U.S. courts," an embassy statement said.

The suspects' lawyers had sought to persuade Thomas and a second senior judge to prevent the extradition on medical and human rights grounds. It had already been approved by British courts, the European Court of Human Rights and Britain's home secretary.

Thomas said the judges are satisfied that the European court had not fallen into error "and was justified in drawing the conclusion that it did."

It was "unacceptable" that extradition proceedings should take so long, he said. They should last "months, not years," he said.

The five men had taken every possible effort to prevent their extradition, he added.

The legal process in the case of al-Fawwaz and Bary has lasted 14 years.

In a statement read out on his behalf outside the court, Ahmad -- who has been detained without trial since 2004 -- claimed a moral win.

"Today I have lost my eight-year and two-month battle against extradition. I would like to thank all those over the years who supported me and my family: lawyers, politicians, journalists and members of the public from all walks of life," it said.

"By exposing the fallacy of the UK's extradition arrangements with the U.S., I leave with my head held high having won the moral victory."

His father, Ashfaq Ahmad, said the UK police, prosecutors and judiciary had "colluded to implement a pre-determined decision which was made in Washington."

He added: "We will never abandon our struggle for justice and the truth will eventually emerge of what will be forever remembered as a shameful chapter in the history of Britain."

The ruling followed a three-day last-ditch hearing this week.

Lawyers for al-Masri told the court their client suffers from deteriorating mental health and was unfit to plead.

However, the judges dismissed that argument in Friday's ruling. "There is nothing to suggest it would be unjust or oppressive to order his extradition," Thomas wrote.

The cases of Babar Ahmad and Talha Ahsan are both linked to a website called azzam.com, which U.S. prosecutors say was run by the two men to support terrorism around the world.

Meanwhile, Al-Fawwaz and Bary are accused of being al Qaeda associates of Osama bin Laden in London during the 1990s.

Lawyers for al-Fawwaz presented evidence, including some arising from an interview by British intelligence officers with an al Qaeda informer, which they say discredits the case against him.

Presenting medical reports, lawyers for Bary said he had a deteriorating mental illness, making him unfit for detention in a high-security Supermax prison, where he is expected to be held if sent to the United States.