Three British men along with an associate have been jailed for planning mass suicide attacks in the UK in collaboration with al-Qaeda.
Irfan Naseer, Irfan Khalid, Ashik Ali and Rahin Ahmed, the associate, were sentenced on Friday after their conviction at London's Woolwich Crown Court in February on 12 counts.
The four men, who had all pleaded guilty to engaging in planning terrorist acts, had been charged between December 2010 and September 2011.
Prosecutors said that although their targets remained unidentified, the attacks could have been as deadly as the 2005 London bombings, which killed 52 people on underground trains and on a bus.
Delivering the sentences, Judge Richard Henriques said: "Clearly nothing was going to stop you, short of intervention of the authorities. I have no doubt you would have continued with your plan but for that intervention."
He added: "Many deaths were planned by a determined team of individuals who were fully radicalised and you, Naseer, were their leader."
Naseer, who the judge said was a "skilful bomb-maker", was jailed for life and told he must serve at least 18 years in prison, the Press Association reported.
Ahmed was given a 17-year jail term for terrorist financing.
Khalid, who had boasted the planned attack would be "another 9/11", was given 23 years and will spend at least 12 behind bars before he can be released, while Ali was jailed for 20 years with a minimum of 10 in custody.
"Your plot had the blessing of al Qaeda and you intended to further the aims of al Qaeda," Judge Henriques said.
Naseer and Khalid had spent time at training camps in Pakistan where they had learnt how to make bombs, mix poisons and fire guns.
The court was told they had prepared "martyrdom videos" in anticipation of their suicide campaign.
With the help of others, the three plotters had intended to detonate eight rucksack bombs in a mass attack and possibly use timers to set off other devices in crowded places.
They had also considered welding knife blades to a truck and ramming it into a crowd of people, prosecutors said.
The group tried to fund their plot by posing as street collectors for the Muslim Aid charity organisation, raising £12,000 for themselves in this way.
But they were forced to apply for tens of thousands of pounds in loans after their associate Ahmed lost more than £9,000 trading on foreign currency markets.