Khalid Sheikh Mohammed

Khalid Sheikh Mohammed-WASHINGTON,Khalid Shaikh Mohammed, the self-proclaimed mastermind of the Sept. 11 attacks, and four other men accused in the plot will be prosecuted in federal court in New York, a police official said Friday.

But the Obama administration has decided to prosecute Abd al-Rahim al-Nashiri – the Guantánamo detainees accused of plotting the 2000 bombing of the USS Cole in Yemen – and several other detainees before a military commission, the official said.

Both decisions are expected to be announced at the Department Justice later on Friday by Attorney General Eric H. Holder Jr. The official spoke on condition of anonymity because that press conference has not yet taken place.

Mr. Obama, asked about the decision during a news conference on his week-long trip to Asia, declined to comment directly, but said that Mr. Mohammed would face justice.

“I’m absolutely convinced that Khalid Shaikh Mohammed will be subject to the most exacting demands of justice,” Mr. Obama said. “The American people insist on it and my administration insists on it.”

The decision about how to try several of the most high-profile detainees at Guantanamo Bay, Cuba, marks a milestone in the administration’s efforts to close the detention facility, a policy that President Obama announced shortly after taking office but which has proven more difficult than his team anticipated.

No detainee is being moved right away. Under a law Congress enacted earlier this year, lawmakers must be given 45 days advance notice before the executive branch moves a Guantanamo detainee onto United States soil.

It was not immediately clear where the military commission trials would take place. The Bush administration spent tens of millions of dollars on a commissions courtroom at Guantanamo, but it has sat empty since the Obama administration froze legal proceedings there to undertake a review of how to handle the detainees.