Friday night, intelligence sources tell NBC News that an intense manhunt is under way for five suspects in the airline bombing plot. And there are concerns that as many as 20 connected to this plot may still be at large.
Friday, forensic teams swarmed homes of the suspects, and the British government took the extraordinary step of releasing the names of 19 of the 24 arrested, and also froze their assets. One suspect was later released.
A father whose three sons were arrested was devastated. A friend spoke for the family.
"Anyone who knows them would swear on the Quran that they are innocent without shadow of a doubt," he says. "They went to pray, that's their guilt."
Those arrested here range in age from 17 to 35. Nearly all are of Pakistani descent, most are middle class, two are said to be women — one of them pregnant.
Suspect Don Stewart Whyte converted to Islam only six months ago.
"He's not a radical, when you see him, he was just, he did look up Islam a lot like recently, but he only looked it up in like the way that affected his life," says his friend says Jan-Sher Bhatti.
Amjad Sawar had a listing on a dating Web site. He claims to be kind and honest.
The suspects come from different parts of Britain, with the largest cluster from London, another group from a London suburb, and two from the industrial city of Birmingham.
Counterterror officials say some members of the cell did not know each other. Sources say the common link was that each group communicated with the ringleader in Pakistan.
Friday, Pakistani authorities identified the ringleader as Rashid Rauf — a British citizen — whose brother also was arrested in Britain.
"Rauf is not a senior al-Qaida operative, but he's typical of the type of facilitator so important for terrorist operations inside the United Kingdom," says Roger Cressey, an NBC terrorism analyst.
Pakistani officials tell NBC that one critical element of the investigation was the arrest of a man near the Afghan border about 10 days ago, an arrest that the Pakistani ambassador to the U.N. says triggered a chain reaction.
"Some information we obtained through this investigation led us to the actions that have now been taken," says Munir Akram.
Intelligence sources say another key break was that the U.S. intercepted communications between the plotters in Pakistan and Britain. They say that while some plotters received explosives training in Pakistan, there is no evidence they met with any senior al-Qaida commanders there.