Passengers told federal investigators that Abdulmutallab went to the bathroom for about 20 minutes. When he returned to his seat, he said he had an upset stomach and pulled a blanket over himself.
Jasper Schuringa, a Dutch man who was sitting behind him, was one of the passengers and crew members praised for banding together to stop the suspect after first hearing a sound like firecrackers.
Schuringa said he saw smoke and flames billowing from the suspect's lap and lunged onto Abdulmutallab's seat to take a burning object he was holding between his legs.
"When I saw the suspect he was getting on fire and I freaked of course, and without any hesitation jumped over the seats and jumped to the suspect because I was thinking, like, he's trying to blow up the plane," he told the CNN news channel.
"I pulled the object from him and tried to extinguish the fire with my hands and threw it away," he said.
As the cabin filled with smoke, Schuringa and crew dragged the suspect to the front and contained him, while others put out the fire.
"We took him to first class and there we stripped him and contained him with handcuffs and made sure he had no more weapons or bombs on him," Schuringa said.
US media reported that Abdulmutallab had admitted to trying to ignite explosive powder taped to his leg by using a syringe filled with chemicals.
US officials described the incident as an "attempted act of terrorism".
US media cited officials saying the suspect had told interrogators that al-Qaeda operatives in Yemen had been giving him the equipment and instructions on how to carry out the attack.
Al Jazeera's John Terrett, reporting from Washington, said that US news organisations were reporting that these claims actually were true.
|Abdulmutallab is the son of a prominent Nigerian banker [Reuters]
"First we didn't know if this was an al-Qaeda operation or whether this was a man trying to attract attention to himself in all the wrong ways. But as the past day has gone by, it does look more and more as if there may indeed be some al-Qaeda link."
Eric Holder, the US attorney general, said authorities would broaden the investigation beyond Abdulmutallab.
He vowed to "use all measures available to our government to ensure that anyone responsible for this attempted attack is brought to justice".
British police on Saturday conducted a search at an apartment building in a West London neighbourhood where Abdulmutallab is said to have lived.
"We are in liaison with the US authorities and searches in London are being conducted as part of ongoing enquiries," the Reuters news agency quoted a spokeswoman for the Metropolitan Police as saying.
"The searches are being carried out at more than one address," she said.
Terror watch list
Abdulmutallab was on the US Terrorist Identities Datamart Environment (TIDE) security watch list, which includes about 550,000 people.
However, the Nigerian was not on the smaller Terrorist Screening Data Base (TSDB) and was not flagged for mandatory extra airport security screening or included on the "no fly" list.
"There's no one thing that is going to make flying 100 per cent safe. What you want to do is to cover many bases and overlap the security measures"
aviation security analyst
US authorities told The Associated Press news agency that the suspect came to the attention of intelligence officials in November when his father went to the
US embassy in the Nigerian capital, Abuja, to express concerns about his son.
One of Abdulmutallab's uncles said that he had been estrained from the family because of his extreme religious views.
Al Jazeera's Yvonne Ndege, reporting from Abuja, said Nigerian authorities had launched an investigation, concentrating on how the suspect breached security and boarded the aircraft.
He is believed to have started his journey in Lagos before the flight stopped at Amsterdam's Schiphol airport on the way to Detroit.
Ndege said that Abdulmutallab's family had been called to the capital for questioning, but that there was no suggestion that they were involved in illegal activities.
"There's been shock, condemnation and disbelieve from millions of Nigerians ... They simply cannot believe that the son of a prominent banker ... from a very privileged family, somebody who was educated privately in some of the world's best educational institution could be involved in this kind of event."
Passengers travelling on Saturday and Sunday felt the consequences of the attempted attack.
Several airlines told their passengers that new US regulations prevented them from leaving their seats from an hour before landing.
Douglas Laird, an aviation security analyst, told Al Jazeera that technology has to be improved to ensure safety onboard aircraft.
"Schiphol [Amsterdam] is one of the best airports in Europe in a security sense, very very efficient, very thorough," he said.
"The problem is... if you want to find what people are hiding on their bodies and bringing on to the airplane, you need to do a body scan.
"But there's no magic bullet. There's no one thing that is going to make flying 100 per cent safe. What you want to do is to cover many bases and overlap the security measures. Hopefully that will cover what you are looking for."