[Source: Reuters]

The man accused of masterminding the Sept. 11 attacks, Khalid Sheikh Mohammed, and two of his accomplices, held at the U.S. military prison at Guantanamo Bay, Cuba, have agreed to plead guilty, the Pentagon said on Wednesday.

The Pentagon did not elaborate on the plea deals.

A U.S. official, speaking on condition of anonymity, states the plea deals almost certainly involved guilty pleas in exchange for taking the death penalty off the table.

The official said the terms of the agreement had not been publicly disclosed but acknowledged a plea for a life sentence was possible.

Mohammed is the most well-known inmate at the detention facility in Guantanamo Bay, which was set up in 2002 by then-U.S. President George W. Bush to house foreign militant suspects following the Sept. 11, 2001 attacks on the United States.