* Man tries to ignite explosive as plane nears Detroit
* Suspect, 23-year-old Nigerian, is injured, detained
* Explosive device said to be 'fairly sophisticated'
* Dutch authorities start probe
By Kevin Krolicki
DETROIT, Dec 26 (Reuters) - A Nigerian man believed to be linked to al Qaeda militants was in custody on Saturday after he tried to ignite an explosive device on a U.S. passenger plane as it approached Detroit, U.S. officials said.
The suspect, who suffered extensive burns, was overpowered by passengers and crew on the Christmas Day flight from Amsterdam. The passengers, two of whom suffered minor injuries, disembarked safely from the Delta Air Lines plane.
"We believe this was an attempted act of terrorism," a White House official told Reuters.
The flight had left Amsterdam on Friday and Dutch counter-terrorism authorities said they were trying to figure out where the suspect had come from, how he had been screened and how he had managed to board the flight.
Representative Peter King of New York, the senior Republican on the House of Representatives Homeland Security Committee, said the explosive device was "fairly sophisticated," and the suspect was a 23-year-old Nigerian.
Federal officials identified him as Abdul Farouk Abdulmutallab, according to The New York Times and the Washington Post. ABC News and NBC News reported that he attends University College London, where he studied engineering.
Abdulmutallab tried to ignite the device or mixture as the aircraft was approaching Detroit, officials said.
King told CNN the suspect was listed in a database as having a connection to militants.
"My understanding is...that he does have al Qaeda connections, certainly extremist terrorist connections, and his name popped up pretty quickly" in a search.
King said the suspect started his journey in Nigeria.
"How sophisticated he was, I don't know," he said. "But again, it was a fairly sophisticated device. I would say we dropped the ball on this one."
Security at Amsterdam's Schiphol Airport has been tightened, in line with increased measures around the world for U.S.-bound flights requested by American authorities. The British government told UK airports to step up checks on flights bound for the United States.
Judith Sluiter, a spokeswoman for Dutch counter-terrorism agency NCTb, said it had started a probe into the incident, trying to determine where the suspect originated from.
"He did not go through passport control," a Dutch military police spokesman said.
The spokesman confirmed he transferred from another flight of uncertain origin.
An Air France-KLM (AIRF.PA) spokeswoman said passenger lists were confidential and she could not confirm Abdulmutallab started his journey with a KLM flight to Amsterdam from Lagos.
The Nigerian government ordered security agencies to investigate the incident and said they would cooperate fully with the American authorities.
"All the necessary security measures are in place in Nigeria. Any passenger, including crew members, on any flight is subject to the same security screening," a spokesman for Nigeria's Federal Airport Authority said.
The aircraft, Northwest Airlines flight 253, was an Airbus 330 carrying 278 passengers. Delta Air Lines (DAL.N) has taken over Northwest.
Passenger Richelle Keepman said the incident was terrifying.
"I thought -- I think we all thought we weren't going to land, we weren't going to make it," Keepman told NBC News.
Another passenger, Melinda Dennis, said the man was severely burned.
"His entire leg was burned. They required a fire extinguisher as well as water to put it out," she told NBC.
"You could smell the smoke when we landed. You could smell the scent of something being burned when we landed."
Once on the ground, the aircraft was moved to a remote area at Detroit's airport where all baggage was being rescreened, the Transportation Security Administration said.
Citing U.S. officials, the Wall Street Journal said the Nigerian had told investigators that al Qaeda operatives in Yemen had given him the device and instructions on how to detonate it.
But NBC, citing anti-terrorism officials, said he claimed to have been acting on his own."
King said investigators were looking into whether the incident was part of a larger plot. There is a "world-wide alert to make sure this is not part of a larger overall scheme," he said.
The New York Times, citing a senior Homeland Security official, said the device was made from a mixture of powder and liquid and was more incendiary than explosive.
The official said Abdulmutallab told law enforcement authorities he had explosive powder taped to his leg and used a syringe filled with chemicals to mix with the powder in an attempt to cause an explosion."
The Department of Homeland Security said security measures had been stepped up.
The attempt appeared similar to one eight years ago when a British-born man, Richard Reid, tried but failed to blow up a trans-Atlantic jumbo jet by lighting explosives stuffed into his shoes. Reid, a follower of al Qaeda leader Osama bin Laden, is serving a life sentence in a U.S. prison.
It also is the latest in a string of terrorism-related plots in the United States over the past few months. Al Qaeda militants carried out the Sept.11, 2001, attacks in the United States in which three passenger planes were hijacked.
Additional reporting by Tabassum Zakaria in Hawaii, Todd Eastham, Jeremy Pelofsky, Mohammad Zargham and Jim Wolf in Washington and Peter Bohan in Chicago; Editing by Angus MacSwan