DETROIT (Reuters) - A federal judge entered a not guilty plea on Friday on behalf of Umar Farouk Abdulmutallab, the 23-year-old Nigerian accused in the attempted bombing of a Detroit-bound airplane that prompted a sweeping review of U.S. security procedures.
Abdulmutallab, who shuffled into court in leg irons, answered questions from U.S. Magistrate Mark Randon, who entered the not guilty plea after his court-appointed lawyer said the defendant would "stand mute."
He was arraigned on six charges including attempted murder and the attempted use of a "weapon of mass destruction" to bring down a plane carrying 289 other people.
President Barack Obama took responsibility on Thursday for security failures that allowed Abdulmutallab to board the plane in Amsterdam and ordered reforms aimed at thwarting attacks.
The attempted bombing on Christmas Day prompted a spate of airline security scares that have shut down airports and stranded jittery passengers.
On Friday, Boston's international airport closed for half an hour because of a suspicious smell that officials said may have been de-icing fluid and an AirTran flight from Atlanta to San Francisco was diverted because of an unruly passenger. The U.S. military said two fighter jets were scrambled to escort the plane to Colorado Springs, Colorado.
Officials say Abdulmutallab tried to ignite explosives concealed in his clothing on the flight but was subdued by other passengers fire broke out around his seat.
CBS News, citing British Intelligence, reported on Friday that Abdulmutallab told investigators after his arrest that close to 20 other young Muslim men were being prepared in Yemen to use the same method to blow up airliners.
Linked to a Yemen-based branch of al Qaeda, Abdulmutallab has been held in a federal prison near Detroit.
His first court appearance took less than three minutes, and set the stage for a trial that legal experts said is weighted heavily in the government's favor, given the evidence and the number of witnesses.
Abdulmutallab wore a white T-shirt, tan pants and tennis shoes and was escorted by a pair of federal marshals.
"Do you understand the charges contained in the indictment?" Randon asked.
"Yes I do," Abdulmutallab replied softly.
Randon asked Abdulmutallab if he understood the sentence associated with the charges, which could include life in prison. "Yes, I do," Abdulmutallab said.
Miriam Siefer, the lawyer representing Abdulmutallab, waived his right to a detention hearing and he was returned to U.S. custody.
Police closed off the snow-covered street approaching the federal building and limited the number of observers in court to fewer than 80 witnesses and reporters. Three bomb-sniffing dogs checked those arriving for the hearing.
A prominent Nigerian attorney, Maryam Uwais, said she was in court to act as an observer at the request of Abdulmutallab's family, who did not attend.
Hebba Aref, a lawyer from Bloomfield Hills, Michigan, sat six rows in front of the suspect on Northwest Airlines Flight 253. She was sitting in the courtroom when he appeared.
"I felt something in the pit of my stomach and my heart. I obviously wasn't frightened or anything, but it was a little strange for me to see him again in different circumstances," said Aref.
Outside court, about a dozen people held up signs reading "Islam is against terrorism" and "Not in the name of Islam."
Meanwhile, U.S. Attorney General Eric Holder said the use of full-body scans was a necessary invasion of privacy and he predicted travelers would soon get as used to them as they have become to removing their shoes at security checkpoints.
"We have to use all the means we can to ensure that people can fly safely.
The impact of if that had been successful in Detroit, the ripple effects of that on our economy, on our system of commerce, would have been huge," Holder told a civic group in Florida.
In Washington, former top U.S. intelligence official John McLaughlin was appointed to head a task force to examine why the United States failed to prevent the bombing attack and the November shootings at the Fort Hood Army base in Texas.
He will lead a small group of national security experts to examine the events leading to both security failures and to propose reforms to better detect future attacks.