Self-proclaimed Sept. 11 mastermind Khalid Sheikh Mohammed and four other Guantanamo Bay detainees will be sent to New York to face trial in a civilian federal court, an Obama administration official said Friday.

The official said Attorney General Eric Holder plans to announce the decision later in the morning.

The official is not authorized to discuss the decision before the announcement, so spoke on condition of anonymity.

Bringing such notorious suspects to U.S. soil to face trial is a key step in President Barack Obama's plan to close the terror suspect detention center at Guantanamo Bay, Cuba. Obama initially planned to close the detention center by Jan. 22, but the administration is no longer expected to meet that deadline.

The New York case may also force the court system to confront a host of difficult legal issues surrounding counter-terrorism programs begun after the 2001 attacks, including the harsh interrogation techniques once used on some of the suspects while in CIA custody. The most severe method — waterboarding, or simulated drowning — was used on Mohammed 183 times in 2003, before the practice was banned.

Holder will also announce that a major suspect in the bombing of the U.S.S. Cole, Abd al-Rahim al-Nashiri, will face justice before a military commission, as will a handful of other detainees to be identified at the same announcement, the official said.

It was not immediately clear where commission-bound detainees like al-Nashiri might be sent, but a military brig in South Carolina has been high on the list of considered sites.

The actual transfer of the detainees from Guantanamo to New York isn't expected to happen for many more weeks because formal charges have not been filed against most of them.

The attorney general has decided the case of the five Sept. 11 suspects should be handled by prosecutors working in the Southern District of New York, which has held a number of major terrorism trials in recent decades at a courthouse in lower Manhattan, just blocks from where the World Trade Center towers once stood.

Holder had been considering other possible trial locations, including Virginia, Washington, DC, and a different courthouse in New York City. Those districts could all end up conducting trials of other Guantanamo detainees sent to federal court later on.

The attorney general's decision in these cases comes just before a Monday deadline for the government to decide how to proceed against 10 detainees facing military commissions.

In the military system, the five Sept. 11 suspects had faced the death penalty, but the official would not say if the Justice Department would also seek capital punishment against the men once they are in the federal system.

The administration has already sent one Guantanamo detainee, Ahmed Ghailani, to New York to face trial, but chose not to seek death in that case.

At the last major trial of al-Qaida suspects held at that courthouse in 2001, prosecutors did seek death for some of the defendants.

Mohammed already has an outstanding terror indictment against him in New York, for an unsuccessful plot called "Bojinka" to simultaneously take down multiple airliners over the Pacific Ocean in the 1990's.

Some members of Congress have fought any effort to bring Guantanamo Bay detainees to trial in the United States, saying it would be too dangerous for nearby civilians. The Obama administration has defended the planned trials, saying many terrorists have been safely tried, convicted, and imprisoned in the United States, including the 1993 World Trade Center bomber, Ramzi Yousef.

Mohammed and the four others — Waleed bin Attash, Ramzi Binalshibh, Mustafa Ahmad al-Hawsawi and Ali Abd al-Aziz Ali — are accused of orchestrating the attacks that killed 2,973 people on Sept. 11, 2001.