Lawyers for five alleged 9/11 plotters urged a military judge Tuesday to allow them two days to visit the super-secure prison and cells where they are being held.

The defendants, meanwhile, boycotted proceedings on the second day of hearings at the Guantanamo Bay prison camp to prepare for their trial on charges of murdering nearly 3,000 people on September 11, 2001.

"You want to sleep with your client?" Colonel James Pohl, the military judge presiding over the case, retorted. "What would be the purpose of spending two days in the facility?"

Noting that no outsider has ever been inside the Camp 7 maximum security facility, the lawyers said they wanted to experience first hand the conditions in which their clients were being held.

David Nevin, the lawyer defending Mohamed, said it would be "for us to be able to observe exactly what life in this camp is like, particularly for a person that was tortured."

"It would be the best way to have a better understanding of their conditions of confinement," said Major Walter Ruiz, the military lawyer defending Saudi national Mustapha al-Hussawi.

Prosecutor Major Robert McGovern responded by proposing a two-hour tour of the facility, calling it "the safest way" to meet the requirement for a "confinement visit."

But defense lawyer Kevin Bogucki, who represents Yemeni national Ramzi Binalshibh, called that "unacceptable."

A two-hour tour, he said, would be "like a Jungle Cruise at Disney World, you're not allowed to leave the boat."

Jim Harrington, another lawyer for Binalshibh, said: "Being in the place is the only way to feel it." He alleged that in other prisons he had seen "corners where you could take people and beat them."

"Forty-eight hours is the very minimum," insisted Cheryl Bormann, who is defending Yemeni national Wallid bin Attash.

Mohammed and the four other accused 9/11 plotters appeared on Monday, but failed to leave their cells on Tuesday, as is their right.

An officer from the prison at Guantanamo, where the accused and other terror suspects are detained, said the defendants informed him verbally and in writing that they would not attend the proceedings on Tuesday.

One of the suspects, bin Attash, said at Monday's hearing that the defendants had no "motivating factor" to come to court.

"Our attorneys are bound and we are bound also," he said. "The government doesn't want us to say anything, to do anything."

Hearings at the maximum security court are broadcast over closed-circuit television with a 40-second delay to journalists and observers in a nearby room, a media center and at Fort Meade in Maryland, outside Washington.

But a portion of the hearing was censored Monday and the feed was cut off when lawyers began discussing the CIA prisons where the five accused were detained and interrogated before being transferred to Guantanamo.

The defense maintains that the CIA "black sites," whose location remains classified, should be preserved because they constitute potential evidence that the five were tortured at the prisons.

The five suspects underwent harsh interrogations before they were taken to Guantanamo, including water boarding, or simulated drowning. Mohammed was subjected to water boarding 183 times, according to the CIA.

Military prosecutors argue that any discussion of the CIA's detention program has to remain classified to protect intelligence sources and methods that could prevent a future attack.

The judge expressed frustration on Monday that "an external body" had apparently cut off the audio and video feed.