Updated

They were very ordinary would-be terrorists, with big plans but bad luck.

On Thursday, a jury convicted three young British men -- including an unemployed pharmacy graduate nicknamed Chubbs -- of being ringleaders of an Al Qaeda-inspired plot to explode knapsack bombs in crowded parts of Birmingham, England's second-largest city.

The men had pleaded not guilty, but were recorded discussing plans for attacks that one said would be "another 9/11."

A jury at Woolwich Crown Court in London found 27-year-old Ashik Ali; Irfan Khalid, also 27; and 31-year-old Irfan Naseer -- nicknamed Big Irfan, or Chubbs -- guilty of multiple counts of preparing for terrorism.

Judge Richard Henriques told the men they face life in prison when sentences are imposed in April or May. "It's clear that you were planning a terrorist outrage in Birmingham," the judge said.

But the men failed -- thanks in part to official surveillance and their own incompetence.

Prosecutors said Naseer and Khalid traveled to Pakistan for terror training, where they learned details of poisons, bomb-making and weaponry and made "martyrdom videos" justifying their planned attacks.

On their return to England in July 2011, they began to recruit others to the plot and to raise money by posing as street collectors for Muslim charities. They also began experimenting with chemicals, the prosecutor said, aided by Naseer's university degree in pharmacy.

But many of the group's plans soon went awry. Four other young men dispatched by the plotters to Pakistan for terrorist training were sent home within days when the family of one man found out. The four have pleaded guilty to terrorism-related offenses.

Rahin Ahmed, an alleged co-conspirator described in court as the cell's "chief financier," tried to increase the group's budget by trading the money it made from bogus charity fundraising on the financial markets. Instead, he lost the bulk of the terror cell's money through his "unwise and incompetent" trading, prosecutor Brian Altman said.

Among the pieces of evidence at the four-month trial was a sports injury cool pack, which prosecutors said Naseer had mistakenly believed would contain ammonium nitrate, a key bomb-making ingredient.

The group also considered other outlandish attacks, including tying sharp blades to the front of a truck and driving it into a crowd. Naseer was heard talking about the possibility of mixing poison into creams such as Vaseline or Nivea and smearing them on car handles to cause mass deaths.

Despite the amateurish nature of some of their efforts, officials said the group was serious about spreading terror.

The men were "the real deal" and, if successful, would have perpetrated "another 9/11 or another 7/7 in the U.K.," said Detective Inspector Adam Gough, the case's senior investigating officer.

Among evidence found by investigators was a partially burned note written by Naseer detailing how to make what an expert witness said would have been a viable bomb -- although no evidence of such an explosive was recovered.

The jury agreed with prosecutors that the trio were the senior members of a home-grown terror cell inspired by the anti-Western sermons of U.S.-born Muslim cleric Anwar al-Awlaki, who was killed in Yemen in a U.S. drone strike in September 2011.

Prosecutors said the men ultimately gravitated toward a plan to detonate up to eight knapsack bombs -- either on timers or in suicide attacks -- in a bid to cause carnage on a scale larger than the July 7, 2005, London transit bombings, which killed 52 commuters.

Police said the terrorist conspiracy was the most significant uncovered in Britain since a plot to blow up airliners in mid-air was foiled in 2006. However, no targets had been chosen and no bombs built when the men were arrested in a police swoop in September 2011 in Birmingham, central England. Twelve suspects were arrested in all, several of whom have pleaded guilty to terrorism offenses.

Fatally for the plot, by mid-2011 the men were under surveillance by police and the intelligence services. Their car was followed and their safe house bugged.

Naseer was recorded plotting about knapsack bombs going "boom, boom, boom everywhere," while Khalid said the attack would be "revenge for everything, what we're doing is another 9/11."

On the recordings, the trio spoke of themselves as martyrs and jihadi warriors -- but also, tellingly, compared themselves to the hapless would-be bombers of British comedy film "Four Lions."

Ali was recorded saying to his ex-wife: "Oh, you think this is a flipping `Four Lions.' We're one man short."

Raffaello Pantucci, a terrorism expert at the Royal United Services Institute think tank, said the foiled plot bore the hallmarks of a decentralized Al Qaeda, in which local cells operate independently, often after receiving rudimentary training.

He said that "the time spent training foreign fighters by Al Qaeda or affiliated networks is now being constrained because there is the threat of drone strikes" on the Pakistan-Afghan border.

"The command and control element is drawing back," he said. "It has a negative impact on their capacity to launch attacks because people aren't being trained as well. There is sometimes a clownish element to it."