WASHINGTON - Self-proclaimed Sept. 11 mastermind Khalid Sheikh Mohammed and four other Guantanamo Bay detainees will be brought to trial in a civilian U.S. courthouse in New York, near the site of the devastating 2001 terror attacks. Prosecutors expect to seek the death penalty.

Attorney General Eric Holder announced the long-awaited and politically fraught decision at a news conference Friday. He also said five other Guantanamo detainees, including a major suspect in the bombing of the USS Cole warship, Abd al-Rahim al-Nashiri, will be tried through the military commission process.

Holder said the Sept. 11 defendants should be tried where their crimes occurred. Nearly 3,000 people died when the World Trade Center towers were brought down by two hijacked jetliners, another hijacked jet hit the Pentagon and a fourth crashed in the state of Pennsylvania.

"After eight years of delay, those allegedly responsible for the attacks of September the 11th will finally face justice," Holder said. "They will be brought to New York -- to New York -- to answer for their alleged crimes in a courthouse just blocks away from where the twin towers once stood."

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 centre at Guantanamo Bay, Cuba. Obama initially planned to close the prison by Jan. 22, but the administration is no longer expected to meet that deadline.

"For over 200 years our nation has relied upon a faithful adherence to the rule of law," Holder said. "Once again, we will ask our legal system in two venues to answer that call."

The plan that Holder outlined is a major legal and political test of Obama's overall approach to terrorism. If the case suffers legal setbacks, the administration will face second-guessing from those who never wanted it in a civilian courtroom. And if lawmakers get upset about terrorists being brought to their home regions, they may fight back against other parts of Obama's agenda.

Early reaction was divided along political lines.

Senate Republican leader Mitch McConnell said bringing the terrorism suspects into the U.S. "is a step backwards for the security of our country and puts Americans unnecessarily at risk."

Republican Sen. Jon Kyl said bringing Mohammed to New York for trial also could result in the disclosure of classified information. Kyl maintained that the trial of Omar Abdel Rahman, the so-called "blind sheik" who was tried for a plot against some two-dozen New York City landmarks, caused "valuable information about U.S. intelligence sources and methods" to be revealed to the al-Qaida terrorist network.

Former President George W. Bush's last attorney general, Michael Mukasey, a former federal judge in New York, also objected: "The Justice Department claims that our courts are well suited to the task. Based on my experience trying such cases and what I saw as attorney general, they aren't."

But Senate Judiciary Committee chairman Patrick Leahy, a Democrat, said the federal courts are capable of trying high-profile terrorists.

"By trying them in our federal courts, we demonstrate to the world that the most powerful nation on earth also trusts its judicial system -- a system respected around the world," Leahy said.

Some family members of Sept. 11 victims were angered by the decision.

"We have a president who doesn't know we're at war," said Debra Burlingame, whose brother, Charles Burlingame, had been the pilot of the hijacked plane that crashed into the Pentagon. She said she was sickened by "the prospect of these barbarians being turned into victims by their attorneys," if the trial winds up focusing on allegations that the suspects were tortured after their capture.

Some Sept. 11 families have supported the move toward public trials, saying they want to see justice done openly.

"If we claim to be a country that believes in the rule of law, then we need to behave that way ourselves," said John Leinung, the stepfather of Paul J. Battaglia, who died in the collapse of the twin towers.

"Sept. 11 families are like any other group of people," said Leinung. "There are going to be people with different outlooks, but there are a significant number of us who believe that the federal courts were the proper way to do this."

The New York case may force the court system to confront a host of difficult legal issues surrounding counterterrorism 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.

The five suspects are headed to New York together because they are all accused of conspiring in the 2001 attacks. The five headed to military commissions face a variety of charges but many of them include attacks specifically against the U.S. military.

Holder said no decision had been made on where commission-bound detainees like al-Nashiri might be sent. A military prison in the state of South Carolina has been high on the list of sites under consideration.

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