U.S. District Judge Paul Borman read Abdulmutallab the charges during a 20 minute hearing in the conference room of University of Michigan Medical Center where he is being treated for burns. He smiled as he was wheeled into the room, wearing a green medical gown and blue hospital socks.

He had a bandage on his left thumb and right wrist, and part of the skin on the thumb was burned off.

An affidavit said he had a device containing a high explosive attached to his body. The affidavit said that as Northwest Flight 253 descended toward Detroit Metropolitan Airport, Abdulmutallab set off the device - sparking a fire instead of an explosion.

According to the affidavit filed in U.S. District Court in Detroit, a preliminary analysis of the device showed it contained PETN, also known as pentaerythritol.This was the same material convicted shoe bomber Richard Reid used when he tried to destroy a trans-Atlantic flight in 2001 with explosives hidden in his shoes.

Abdulmutallab began his journey in Nigeria and then changed planes in Amsterdam. Peter King, a Republican congressman, claimed he did not go through full-body image screening at either airport.