Families of people killed in the Sept. 11 terror attack on the U.S. urged President Obama on Thursday to reverse his order to close the Guantanamo Bay prison.

They expressed fear the closure would further delay the long-stalled effort to prosecute the men who have claimed responsibility for the plot.

A contingent of nine relatives of Sept. 11 victims traveled to the U.S. Navy base in Cuba to observe pretrial hearings for several detainees, including five charged in the attack. All said they were impressed with proceedings that seemed fair -- perhaps too fair -- to the accused.

Diane Fairben of Floral Park, New York, whose paramedic son, Keith, died at the World Trade Center, noted the presence of more than a dozen lawyers, a mix of active duty military and civilians, to assist the five defendants even though three are serving as their own attorneys and the other two have asked the court for clearance to do the same.

"These people are being afforded the best legal representation and they are getting a fair shake," Fairben told reporters. "I ask the president to give us a fair shake. We've been shunted to the side for too long and it's getting to be a bit much."

This is the third time that families of Sept. 11 victims have been brought to Guantanamo to observe the Military Commissions. The relatives, who are chosen at random by the government, met with detention center officials and guards but did not see the inside of the prison camps.

In addition to ordering the prison closed, Obama suspended the war crimes trials while reviewing the legal system created in 2006 to prosecute terrorism suspects at Guantanamo. A Justice Department official told a Senate panel last week that the commissions are not likely to withstand new legal challenges and must be changed to grant defendants more rights.

The U.S. now holds about 230 men at Guantanamo and the chief military prosecutor said his office is prepared to file war crimes charges against about 60. It is not known how many will be prosecuted and whether some will be tried in civilian or traditional military courts.

Gordon Haberman of West Bend, Wisconsin, whose daughter Andrea also was killed at the World Trade Center, said the decision to close Guantanamo will not deter al-Qaida from attacking the U.S.

And moving the trials will only provide the defendants with more ways to delay their trials, he said. "If they get into the federal court system they will drag this out for 15 to 20 years."

Judith Reiss of Yardley, Pennsylvania, whose son Joshua was another victim at the World Trade Center, said she voted for Obama but disagrees with his views on Guantanamo and the military trials.

"I don't think there is one family member of a victim or the family of a victim who wants the commissions changed in any way," Reiss said.

The family victims attended two days of hearings called to extend suspension of cases until September and to consider defense requests for more experts and other resources for a mental competency hearing for two men charged in the Sept. 11 attack.

Khalid Sheikh Mohammed, the self-proclaimed mastermind of the plot who has said he wants to plead guilty, refused to attend, apparently because the judge had ruled he would not be allowed to speak because his case was not at issue in the hearing.