KAILUA, Hawaii (AP) - A White House official says it appears to be "an attempted act of terrorism."
Law enforcement and national security officials say a passenger from Nigeria tried to blow up a Northwest Airlines passenger plane as it was landing in Detroit Christmas Day on a flight from Amsterdam.
They say the man claimed to be acting on al-Qaida's instructions.
Officials say passengers subdued the man and may have prevented him from detonating the explosives as the plane made its approach to Detroit.
An intelligence source says the man is being held and treated at a hospital in Ann Arbor.
Rep. Peter King, R-N.Y., identified the suspect as Abdul Mudallad, a Nigerian. King said the flight began in Nigeria and went through Amsterdam en route to Detroit.
A spokeswoman for the Federal Aviation Administration says nothing unusual was reported until the flight was on final approach. She says the pilot then declared an emergency, but landed without incident a short time later.
One U.S. intelligence officials said the explosive device was a mix of powder and liquid. It failed when the passenger tried to detonate it.
Authorities initially believed the passenger had set off firecrackers that caused some minor injuries.
One passenger says the incident took place during the plane's descent. Syed Jafri says he was seated three rows behind the passenger who's now accused of trying to blow up the plane. Jafri says he saw a glow and noticed a smoke smell.
Jafri says a young man who'd been sitting behind Mudallad then jumped on the man with the device.
"Next thing you know, there was a lot of panic," Jafri said.
Passenger Rich Griffith says he was seated too far in the back to see what had happened. But he says he didn't mind being detained on the plane for several hours because of it. He adds, "We can't have what's going on everywhere else happening here.
Mudallad was immediately subdued and was being questioned Friday evening.