(Anahad O'Connor, Peter Baker)
A Nigerian man tried to ignite an explosive device aboard a trans-Atlantic Northwest Airlines flight as the plane prepared to land in Detroit on Friday, in an incident the United States believes was “an attempted act of terrorism,” according to a White House official who declined to be identified.
The device, described by officials as a mixture of powder and liquid, failed to fully detonate. Passengers on the plane described a series of pops that sounded like firecrackers.
Federal officials said the man wanted to bring the plane down.
“This was the real deal,” said Representative Peter T. King of New York, the ranking Republican on the House Homeland Security Committee, who was briefed on the incident and said something had gone wrong with the explosive device, which he described as somewhat sophisticated. “This could have been devastating,” Mr. King said.
The incident is likely to lead to heightened security during the busy holiday season.
It was unclear how the man, identified by federal officials as Umar Farouk Abdulmutallab, 23, managed to get the explosive on the plane, an Airbus A330 wide-body jet carrying 278 passengers that departed from Amsterdam with passengers who had originated in Nigeria. A senior administration official said that the government did not yet know whether the man had had the capacity to take down the plane.
“We’re trying to ascertain exactly what he had and what he thought he was doing, but our sense is he wanted to wreak some havoc here and was attempting to do just that,” the official said. “Whether at the end of the day he had the ability to do that is what I think we’ll be able to pull together over the next several days as we investigate this.”
A senior Department of Homeland Security official said that the materials Mr. Abdulmutallab had on him were “more incendiary than explosive,” and that he had tried to ignite them to cause a fire as the airliner was approaching Detroit.
Mr. Abdulmutallab told law enforcement authorities, the official said, that he had had explosive powder taped to his leg and that he had mixed it with chemicals held in a syringe.
A federal counterterrorism official who asked not to be identified said Mr. Abdulmutallab was apparently in a government law enforcement-intelligence database, but it is not clear what extremist group or individuals he might be linked to.
“It’s too early to say what his association is,” the counterterrorism official said. “At this point, it seems like he was acting alone, but we don’t know for sure.” Although Mr. Abdulmutallab is said to have told officials that he was directed by Al Qaeda, the counterterrorism official expressed caution about that claim, saying “it may have been aspirational.”
The incident unfolded just before noon. “There was a pop that sounded like a firecracker,” said Syed Jafry, a passenger who said he had been sitting three rows ahead of the suspect. A few seconds later, he said, there was smoke and “some glow” from the suspect’s seat and on the left side of the plane.
“There was a panic,” said Mr. Jafry, 57, of Holland, Ohio. “Next thing you know everybody was on him.” He said the passengers and the crew subdued the man.
The suspect was brought by the crew to the front of the plane — Northwest Airlines Flight 253, bearing Delta’s name — and the plane made its descent into Detroit Metropolitan Airport, landing at 11:53 a.m. (The two airlines merged last year.) Once on the ground, it was immediately guided to the end of a runway, where it was surrounded by police cars and emergency vehicles and searched by a bomb-disabling robot.
Sandra Berchtold, a spokeswoman with the Federal Bureau of Investigation’s Detroit office, said F.B.I. agents were at the scene Friday night and were investigating the matter.
One federal official who requested anonymity said Mr. Abdulmutallab had suffered severe burns but was expected to survive. A Michigan state official confirmed that he was being treated at the University of Michigan hospital in Ann Arbor.
President Obama was kept informed throughout the day as he spent Christmas with his family and friends at a secluded Hawaiian beach house. After a secure conference call, he was given several follow-up briefings on paper. John O. Brennan, the White House counterterrorism chief, convened an interagency meeting in the late afternoon to go over what was known about the incident and discuss what precautions should be taken.
A second Department of Homeland Security official said that the Transportation Security Administration used layers of security measures at the nation’s airports and that it would be tightening them as a result of the incident in Detroit.
These measures — some visible to passengers, some not — include bomb-sniffing dog teams, carry-on luggage and passenger screening measures, and plainclothes behavioral-detection specialists inside airport terminals. The official said there were no immediate plans to elevate the nation’s threat level, which has been at orange since 2006.
Mr. King, of the Homeland Security Committee, said there was no indication at this point that anyone else was involved, but he said officials would look back to see if any intelligence signals were missed. “For a while now we have had real concerns about Al Qaeda or terrorist connections in Nigeria,” he said.
Of the device used on Friday, he said, “It appears to be different from explosive devices that have been used before. That is perhaps why it escaped detection. Maybe that is why it made it through.”
Questions have been raised for years about aviation security in Nigeria. Last month, however, the T.S.A. said that standards at the Lagos airport met international criteria for security.
Friday’s incident brought to mind Richard C. Reid, the so-called shoe bomber, who attempted to blow up an American Airlines flight between Paris and Miami in December 2001 by igniting explosives in his shoes. Mr. Reid was subdued by a flight attendant and passengers and the plane landed safely in Boston. Mr. Reid later pleaded guilty to three terrorism-related counts and was sentenced to life in prison. Since then, airline passengers have had to remove their shoes before passing through security checkpoints in American airports.
In August 2006, British authorities uncovered a plot to blow up planes bound for the United States using explosives that would be mixed with liquids on board. Eight men were arrested, and three were convicted in the case this fall. British authorities estimated that as many as 2,000 airplane passengers might have been killed had the plotters been successful. The plot led security officials to limit the amount of liquids and gels that passengers can bring on board in their carry-on baggage.
Anahad O’Connor reported from New York, and Eric Schmitt from Washington. Peter Baker contributed reporting from Hawaii, Eric Lipton from Washington, and Micheline Maynard, Nick Bunkley and Bill Vlasic from Detroit.