Military prosecutors have decided to seek the death penalty for six Guantánamo detainees who are to be charged with central roles in the Sept. 11 terror attacks, government officials who have been briefed on the charges said Sunday.

The officials said the charges would be announced at the Pentagon as soon as Monday and were likely to include numerous war-crimes charges against the six men, including Khalid Shaikh Mohammed, the former Qaeda operations chief who has described himself as the mastermind of the attacks, which killed nearly 3,000 people.

A Defense Department official said prosecutors were seeking the death penalty because "if any case warrants it, it would be for individuals who were parties to a crime of that scale." The officials spoke anonymously because no one in the government was authorized to speak about the case.

A decision to seek the death penalty would increase the international focus on the case and present new challenges to the troubled military commission system that has yet to begin a single trial.

"The system hasnt been able to handle the less-complicated cases it has been presented with to date," said David Glazier, a former Navy officer who is a professor at Loyola Law School in Los Angeles.

In addition to Mr. Mohammed, the other five to be charged include detainees officials say were coordinators and intermediaries in the plot, among them a man labeled the "20th hijacker," who was denied entry to the United States in the month before the attacks.

Under the rules of the Guantánamo war-crimes system, the military prosecutors can designate charges as capital when they present them, and it is that first phase of the process that is expected this week. The military official who then reviews them, Susan J. Crawford, a former military appeals court judge, has the authority to accept or reject a death-penalty request.

A Pentagon spokesman declined to comment on Sunday.

Some officials briefed on the case have said the prosecutors view their task in seeking convictions for the Sept. 11 attacks as a historic challenge. A special group of military and Justice Department lawyers has been working on the case for several years.

Even if the detainees are convicted on capital charges, any execution would be many months or, perhaps years, from being carried out, lawyers said, in part because a death sentence would have to be scrutinized by civilian appeals courts.

Federal officials have said in recent months that there is no death chamber at the detention camp at the United States naval base at Guantánamo Bay, Cuba, and that they knew of no specific plans for how a death sentence would be carried out.

The military justice system, which does not govern the Guantánamo cases, provides for execution by lethal injection in death sentence convictions. But the United States military has rarely executed a prisoner in recent times.

The last military execution was in 1961, when an Army private, John A. Bennett, was hanged after being convicted of rape and attempted murder. Currently, there are six service members appealing military death sentences, according to a recently published article by a lawyer who specializes in military capital cases, Dwight H. Sullivan, a former chief military defense lawyer at Guántanamo.

One official who had been briefed on the war-crimes case said the charges were expected to be lodged against six detainees held at Guantánamo, including Mr. Mohammed, who is said to have presented the idea of an airliner attack on the United States to Osama bin Laden in 1999 and then coordinated its planning.

The official identified the others to be charged as Mohammed al-Qahtani, the man officials have labeled the 20th hijacker; Ramzi bin al-Shibh, said to have been the main intermediary between the hijackers and leaders of Al Qaeda; Ali Abd al-Aziz Ali, known as Ammar al-Baluchi, a nephew of Mr. Mohammed, who has been identified as Mr. Mohammeds lieutenant for the 2001 operation; Mr. al-Baluchis assistant, Mustafa Ahmed al-Hawsawi; and Walid bin Attash, a detainee known as Khallad, who investigators say selected and trained some of the hijackers.

Relatives of the Sept. 11 victims have expressed differing views of potential death sentences, with some arguing that it would accomplish little other than martyring men for whom martyrdom may be viewed as a reward.

But on Sunday, Debra Burlingame, whose brother Charles F. Burlingame III was the pilot of the hijacked American Airlines Flight 77 that was crashed into the Pentagon, said she would approve of an effort by prosecutors to seek the execution of men she blames for killing her brother. Ms. Burlingame said such a case could help refocus the publics attention on what she called the calculated brutality of the attacks, which she said has been largely forgotten.

"My opinion is," she said, "if the death of 3,000 people isnt sufficient for a death penalty in this country, then why do we even have the death penalty?"

(www.nytimes.com)