New Charges in Attempted Christmas Day Bombing

A Nigerian man who authorities say tried to blow up a Christmas Day flight from Amsterdam to Detroit with a bomb concealed in his underwear was indicted on a terrorism charge Wednesday.

A superseding indictment returned by a grand jury accuses Umar Farouk Abdulmutallab of conspiring with others to kill 281 passengers and 11 crew members aboard Northwest Airlines Flight 253. U.S investigators believe the 24-year-old received training and instructions from al Qaeda operatives in Yemen.

As the flight was close to landing at Detroit Metropolitan Airport in suburban Romulus, Abdulmutallab claimed to have an upset stomach and placed a blanket over himself, according to the indictment. He then detonated the bomb, which resulted in a fire, and he was subdued by passengers and flight crew, the indictment said.

CBSNews.com Report: Terror in the U.S.

The new charges against Abdulmutallab are conspiracy to commit an act of terrorism transcending national boundaries and an additional count of possession of a destructive device in furtherance of a crime of violence. They each carry a maximum sentence of life imprisonment.

"The purpose of the superseding indictment is to frame the charges for trial," the U.S. attorney's office said in a statement.

Abdulmutallab is representing himself in the case. Standby counsel Anthony Chambers said Wednesday he had received the superseding indictment, but had no comment on it.

Abdulmutallab is scheduled to be arraigned Thursday in federal court in Detroit.