GUANTANAMO BAY NAVAL BASE, Cuba - Plans to close Guantanamo are not sitting well with the Sept. 11 victims' relatives who sat stunned while two alleged terrorists declared they were proud of their role in the plot.

The U.S. military brought relatives of three Sept. 11 victims to Guantanamo to observe pretrial hearings in the case of five men charged in the plot who could get the death penalty if convicted.

It is a potentially momentous time for the military detention center. President-elect Barack Obama -- whose inauguration is Tuesday -- has said he will close it, and many observers and some officials here expect him to suspend the war crimes tribunals for accused terrorists and move the trials to the U.S.

The five invited relatives of 9/11 victims oppose such a move.

"Though the wheels are grinding, they are turning here and this place must remain open and justice must be served," Andrew Arias, whose brother, Adam, was killed in the attacks, told reporters at the base Monday.

"If not here, where?" said Arias, of South River, N.J. "Keep it open, let's get the job done."

The victims' relatives were in the courtroom audience as two Sept. 11 defendants, Ramzi Binalshibh and Khalid Sheikh Mohammed, proclaimed their role in the worst terrorist attack on U.S. soil.

"We did what we did; we're proud of Sept. 11," said Binalshibh, who has said he wants to plead guilty to charges.

The relatives of the victims said they were outraged by the comments, as well as Mohammed's complaints later about not being able to see his family.

"If they're guilty ... then let's give them the death penalty that they deserve," said Jim Riches of Brooklyn, N.Y., whose 29-year-old firefighter son, Jimmy, was killed at the World Trade Center.

The military tribunal is also holding pretrial hearings this week in the case of Omar Khadr, a Canadian who was 15 when he allegedly killed Sgt. 1st Class Christopher Speer of Albuquerque, N.M., with a grenade during a battle in Afghanistan in 2002.

Lawyers for the Toronto native want to exclude statements they say Khadr made through torture and coercion. Prosecution witnesses denied the allegations. One, identified only as "interrogator 11," characterized some sessions as "lighthearted," and testified that "he always came in smiling and very willing to talk to us."

Khadr's hearing continues Tuesday, though his lawyer and many other observers expect Obama will suspend the commissions before Khadr's trial starts next week.

The judge in the Sept. 11 case, Army Col. Stephen Henley, acknowledged doubts about the future of the hearings, saying one legal matter could be addressed "at later sessions, if later sessions are scheduled."

Obama's nominee for attorney general, Eric Holder, in his confirmation hearing, said the commissions lack sufficient legal protections for the defendants, and said they could be tried in the United States.

"The military commissions should be at the very least suspended immediately," said Gabor Rona, observing as the international legal director of New York-based Human Rights First. "I'm certainly optimistic and hopeful that it will happen as one of the first orders of business."