9-11 chief suspect Khalid Shaikh Mohaammed

U.S. officials say that as many as six detainees held at the U.S. naval base at Guantanamo Bay, Cuba, may face charges as early as this week related to the September 11, 2001 terrorist attacks.

Officials briefed on the case tell reporters that military prosecutors are considering seeking the death penalty against at least one of those expected to be charged. But no final decision has been reached yet.

Among those facing charges is Khalid Sheik Mohammed, who was a former senior aide to Osama bin Laden and who has said he was a principal planner of the airline hijackings and attacks that killed almost 3,000 people in New York City, at the Pentagon and in a Pennsylvania field.

Any trials could draw new legal and political challenges to the military commission system of justice, which has been challenged in U.S. courts on constitutional grounds. And at least two of the detainees involved were subjected to interrogation techniques their defense lawyers may argue amounted to torture.

Mohammed was subjected to a simulated drowning technique called "waterboarding," and Mohammed al-Qahtani was subjected to sleep deprivation and other treatment that a U.S. Defense Department investigation later termed "abusive."