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The arraignment Saturday of the five defendants in the 9-11 attacks stretched into the evening as the self-proclaimed mastermind and his four co-defendants refused to answer the judge’s questions and interrupted the proceeding with prayers and outbursts – all in an apparent attempt to delay the process.

The appearance of the five men at the military tribunal at Guantanamo Bay, Cuba, marked the first time in more than three years that the public has seen Khalid Sheikh Mohammed and the other men.

Mohammed arrived wearing a white turban. His beard is now down to his chest and graying but streaked with red henna.

More than seven hours into the hearing, the judge at the U.S. military base in Cuba hadn't yet read the charges against the men. They face 2,976 counts of murder and other charges related to the 2001 attacks and could receive the death penalty if convicted of the most serious crimes.

All five defendants deferred their pleas until a later date.

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The hearing began at about 9 a.m. local time and almost immediately got delayed when the defendants took off their earphones that provide Arabic translations.

The other defendants -- Ramzi Binalshibh, Walid bin Attash, Ali Abdul Aziz Ali and Mustafa al Hawsawi – joined Mohammed in refusing to answer questions from Army Col. James Pohl, the judge presiding over the proceedings.

At one point, two defendants got up and prayed alongside their defense tables under the watchful eyes of troops arrayed along the sides of the high-security courtroom.

Bin Attash was put in a restraint chair for unspecified reasons, then removed from it after he agreed to behave.

Lawyers for all defendants complained that the prisoners were prevented from wearing the civilian clothes of their choice, in a proceeding equally slowed by technical legal questions about defense complaints about the court’s authority and access to evidence and translators.

Brigadier General Mark Martins, the chief prosecutor of the Pentagon's Office of U.S. Military Commissions told Fox News that he “understands the skepticism” about access to evidence, but some still remains classified.

Mohammed's civilian lawyer, David Nevin, said his client was not responding because he believes the tribunal is unfair. He also suggested Mohammed was not wearing the earphones because it reminded him of being tortured.

All 5 men occasionally looked through what looks like the Koran, magazines, and other reading materials.

Jim Harrington, a civilian attorney for Yemeni defendant Ramzi Binalshibh, said his client would not respond to questions "without addressing the issues of confinement."

Pohl warned he would not permit defendants to block the hearing and would continue without his participation.

He addressed the earpiece issue by bringing the translators into the courtroom to translate out loud and attempted to stick to the standard script for tribunals, asking the defendants if they understood their rights to counsel and would accept the attorneys appointed for them. The men did not respond, not even to acknowledge that they understood the questions.

Cheryl Bormann, a civilian attorney for bin Attash, appeared in a conservative Islamic outfit that left only her face uncovered and she asked the court to order other women present to wear "appropriate" clothing so that defendants do not have to avert their eyes "for fear of committing a sin under their faith."

Attash, whose family was friends with Usama bin Laden’s family, had  insisted Borman wear the black Hajib, saying he would not meet with her unless she was dressed in that way.

He also interrupted the session with an outburst from the defense table in a mix of Arabic and broken English, saying, "Maybe they will kill me and say I committed suicide."

The arraignment comes more than three years after President Obama's failed effort to try the suspects in a federal civilian court and close the prison at the U.S. base in Cuba.

Attorney General Eric Holder announced in 2009 that Mohammed and his co-defendants would be tried blocks from the site of the destroyed trade center in downtown Manhattan, but the plan was shelved after New York officials cited huge costs to secure the neighborhood and family opposition to trying the suspects in the U.S.

Congress then blocked the transfer of any prisoners from Guantanamo to the U.S., forcing the Obama administration to refile the charges under a reformed military commission system.

Six 9-11 family members were in the courtroom with the defendants while more than 100 others watched the proceedings on closed-circuit video feeds in the U.S.

Jim Riches, a retired city firefighter whose son was killed at the World Trade Center, said some people blurted out "C,mon, are you kidding me?" as the defendants became more disruptive.

In the past, during the failed first effort to prosecute them at the U.S. base in Cuba, Mohammed has mocked the tribunal and said he and his co-defendants would plead guilty and welcome execution.

But there were signs Saturday that at least some of the defense teams were preparing for a lengthy fight, planning challenges of the military tribunals and the secrecy that shrouds the case.

The arraignment is "only the beginning of a trial that will take years to complete, followed by years of appellate review," said attorney James Connell, who represents defendant al-Aziz Ali.

"I can't imagine any scenario where this thing gets wrapped up in six months," he said.

Defendants in what is known as a military commission typically do not enter a plea during their arraignment. Instead, the judge reads the charges, makes sure the accused understand their rights and then moves on to procedural issues. All five defendants put off their pleas until a later date. Lawyers were still discussing trial dates Saturday night; another hearing was set for June 12.

Catherine Herridge and the Associated Press contributed to this report.