Obama has ordered his administration to empty and close the controversial prison camps in southeast Cuba by Jan. 22, a deadline that senior Cabinet members have said will likely slip.

There were 215 detainees at Guantánamo on Friday -- six of whom were authorized to face military commission proceedings after Friday's announcement. Afghan Mohammed Kamin, a long-held captive accused of aiding al Qaeda, has a pre-trial hearing on Wednesday.

Holder also decided to permit the chief Pentagon prosecutor to pursue a military commission case against alleged USS Cole bombing conspirator Abd al Rahim al Nashiri, a Yemeni.

The CIA has confirmed that it subjected Nashiri, like Mohammed, to waterboarding in secret black site interrogation, a technique the Obama administration has defined as ``torture,'' which could complicate efforts to present evidence at either trial.

In all, 17 U.S. sailors were killed in the Cole bombing off Aden harbor in October 2000. Thirty-nine others were injured. The badly damaged Cole was brought back to the United States, restored and is now based in Norfolk, Va.

Mohammed and his co-accused have repeatedly boasted of their roles in the Sept. 11 attacks, in which 19 men hijacked four commercial airliners and slammed them into the Pentagon, World Trade Center and a Pennsylvania field. Unclear is whether their comments and letters to a military judge at Guantánamo would be considered evidence at a federal trial.

The American Civil Liberties Union -- a leading critic of military commissions -- hailed the decision to move the 9/11 case to New York but decried the Obama administration's decision to retain war crimes trials in other cases.

``It's disappointing that the administration has chosen to prosecute some Guantánamo detainees in the unsalvageable military commissions system,'' said ACLU Executive Director Anthony D. Romero.

But, he said, the decision to hold the Sept. 11 trial in federal court was ``a huge victory for restoring due process and the rule of law, as well as repairing America's international standing, an essential part of ensuring our national security.''

In response to a reporter's question, Holder defended the decision to split the Guantánamo cases between civilian and military venues.

He said the 9/11 accused would face civilian trial in New York because ``it is a fundamental tenet'' in U.S. law that accused be tried ``where the crimes took place.''

Those facing military trials are accused of war crimes overseas, mostly in Afghanistan but also in the Persian Gulf.