A Detroit court recorded a not guilty plea Friday for the Nigerian man alleged to be behind a failed attempt to blow up a U.S.-bound Northwest Airlines flight on Christmas Day.

Umar Farouk Abdulmutallab, 23, was arraigned on six charges, including the attempted use of a weapon of mass destruction -- a charge that could put him away for life in the United States if he is found guilty.

Abdulmutallab walked into court wearing a white T-shirt, pants, and running shoes.

When asked if he understood the charges against him, he answered "yes" in English.

After that answer, his lawyer said Abdulmutallab would stand mute to the charges. The judge said a not guilty plea would be entered on his behalf.

Abdulmutallab has been labelled the so-called 'underwear bomber' and is alleged to have hidden explosives in his clothing. The FBI says he attempted to ignite the explosives by using chemicals in a syringe as Northwest Airline Flight 253 was descending into Detroit. There were 279 passengers -- including Abdulmutallab -- and 11 crew members on board the plane at the time of the alleged incident.

The U.S. Marshals Service said Abdulmutallab had arrived at the courthouse in a dark SUV that drove into an underground entrance. The vehicle was led and followed by police cars with flashing lights and sirens.

Police set up barricades outside the courthouse to limit pedestrians.

A protester stood outside holding a sign that read: "No U.S. Rights For Terrorists." Others included local Muslim community members who held an American flag and a sign saying: "Not in the name of Islam."

At the courthouse, lawyers from Maryland and Nigeria told The Associated Press that they were there to observe the court on behalf of Abdulmutallab's family. They did not have a role in court but spoke with the suspect's lawyers.

Before the case began, attorneys outside the high profile case say it appears to be a tough one for the accused terror suspect's lawyers to fight. With so many witnesses on board Flight 253 and so much evidence stacked against him already, experts say his defence team will have few options in the courtroom. The evidence also includes statements Abdulmutallab made to the FBI, claiming he trained with al Qaeda operatives in Yemen.

"This is not a case of mistaken identity or a whodunit. For the defence, it's damage control," said Joseph Niskar, a defence lawyer who was involved in a 2001 terrorism case in Detroit that fell apart for the U.S. government.

While John Brennan, U.S. President Barack Obama's counterterrorism advisor has suggested Washington may wish to strike a deal with Abdulmutallab, to obtain information from him about his contacts in Yemen and elsewhere, some attorneys have doubts that would ever happen.

"A person who wants to blow himself up in an airplane over Detroit is not looking to shave some time off in the big house," said Lloyd Meyer, a former terrorism prosecutor at the Guantanamo Bay prison.

"I have no doubt he will welcome the world stage of a federal courtroom. They want a public forum. They want the spotlight to show why they are holy warriors against the great Satan."

Abdulmutallab's lawyer, Detroit's top federal defence lawyer Miriam Siefer did not comment Friday on a possible deal.

Barbara McQuade, the new U.S. attorney in Detroit, said that no such offer has been made so far.

"We'll take the case one step at a time," said McQuade, who handled national-security cases before her current promotion. "If he wants to plead guilty he has the right to do that. ... We need to prepare as if this case is going to trial."

The Detroit Free Press reports that Abdulmutallab was being held in a Federal Correctional Institution in Milan, Mich., about 80 kilometers southwest of Detroit.

Security crackdowns

The case has prompted major security crackdowns at airports around the world, after it was revealed the U.S. security officials failed to focus on "discrete pieces of intelligence" that indicated the accused terror suspect was an al Qaeda operative.

It is alleged that Abdulmutallab purchased his one-way ticket with cash, flew to the U.S. from Amsterdam without any checked baggage and had previously travelled to Yemen. A group that claims to be connected to al Qaeda in that country has claimed responsibility for the attempt.

Overall, Obama has called the security lapses a "systemic failure" and has taken responsibility for the incident. Obama said Thursday that the government would implement new terror watch list guidelines and faster distribution of intelligence reports.

Since the Christmas Day attempt, the U.S. Transportation Security Administration has put air passengers from 14 countries -- including Yemen, Saudi Arabia and Nigeria -- under extra scrutiny if they are flying into the United States.

A number of countries, including Canada, have announced that full body scanners -- capable of seeing through clothing -- will be installed at major Canadian airports by the spring.

With files from The Associated Press